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MINI FLEXIBLE DISK DRIVE MAINTENANCE MANUAL 



TEAC FD-55 (L) 
MINI FLEXIBLE DISK DRIVE 
MAINTENANCE MANUAL 



P/N 10180233-00 Rev. b 

- i - 



TABLE OF CONTENTS 

Title Page 

SECTION 3 THEORY OF OPERATION 300 

3-1 CONSTRUCTION AND FUNCTION 301 

3-1-1 General Block Diagram 301 

3-1-2 Mechanical Section 302 

3-2 CIRCUIT DESCRIPTIONS 307 

3-2-1 Read Write Circuit ., 307 

3-2-2 Control Circuit 315 

3-2-3 Servo Circuit 321 

3-3 FUNCTION OF TEST POINTS AND VARIABLE RESISTORS 322 

3-3-1 Function of Test Points 323 

3-3-2 Function of Variable Resistors 330 



- ii - 



Title Page 
SECTION 4 MAINTENANCE = « = = 4000 

4-1 GENERAL - 4001 

4-1-1 Periodic Maintenance 4001 

4-1-2 Check and Adjustment 4002 

4-1-3 Maintenance Parts Replacement . , - 4004 

4-1-4 Maintenance Jigs and Tools 4 011 

4-2 PRECAUTIONS 4014 

4-2-1 Torque Applied to Screws and Locking Paint 4014 

4-2-2 Handling of Connectors 4015 

4-2-3 Head Cable Treatment ^- . 4020 

4-2-4 Initial Setting of SKA 4022 

4-2-4-1 Cable connection and setting of power supply voltage 4022 

4-2-4-2 Setting of the maximum track number 4025 

4-2-4-3 Setting of step rate and settling time 4026 

4-2-4-4 Level disk calibration 4028 

4-2-4-5 Alignment disk calibration 4030 

4-2-4-6 Humidity setting 4053 

4-2-4-7 Setting of SKA gain 4033 

4-2-5 Others 4034 

4-3 PREVENTIVE MAINTENANCE - - . 4038 

4-3-1 Cleaning of Magnetic Head by Cleaning Disk 4038 

4-3-2 Direct Cleaning {Single sided FDD only) 4040 

4-4 CHECK- AND ADJUSTMENT 4042 

4-4-1 Adjustment of Set Arm Position 4042 

4-4-2 Adjustment of Clamp Arm Position 4044 

4-4-3 Adjustment of Front Lever Position 4046 

4-4-4 Adjustment of Arm Lifter 404S 

4-4-4-1 Double sided FDD 4048 

4-4-4-2 Single sided FDD 4058 

4-4-5 Check of CSS Ass'y 4061 

4-4-6 Check of File Protect Sensor - 4065 

4-4-7 Check and Adjustment of pi sk Rotation Speed . - . . - - . . 4068 

4-4-8 Check and adjustment of Erase Gate Delay 4G71 



- iii - 



Title Page 

4-4-9 Check and Adjustment of Head Touch 4074 

4-4-10 Check and Adjustment of Asymmetry 4O8O 

4-4-11 Check of Read Level 4Qg5 

4-4-12 Check of Resolution ^^gg 

4-4-13 Check and Adjustment of Track Alignment 4093 

4-4-14 Check and Adjustment of Track 00 Sensor _ 4IO2 

4-4-15 Check and Adjustment of Track 00 Stopper 4IO9 

4-4-16 Check and Adjustment of Index Burst Timing 4II3 

4-5 MAINTENANCE PARTS REPLACEMENT 

Replacement of Head Carriage Ass'y 4118 

4-5-2 Replacement of Stepping Motor Ass'y 4122 

4-5-3 Replacement of DD motor Ass'y (Spindle Motor) 4124 

4-5-4 Replacement of Collet Ass'y 4126 

4-5-5 Replacement of Head Load -Solenoid 4127 

4-5-6 Replacement of Track 00 Sensor Ass'y 4129 

4-5-7 Replacement of PCBA MFD Control 4130 

4-5-8 Replacement of PCBA Front OPT 4132 

4-5-9 Replacement of Head Pad (Single sided only) 4133 

4-5-10 Replacement of Front Bezel Ass'y 4135 

4-5-11 Replacement of Front Lever Ass'y 4136 

4-5-12 Replacement of CSS Ass'y 4137 



- iv - 



Title Page 

SECTION 5 DRAWINGS & PARTS LIST 

5-1 CONFIGURATION 

5-2 MECHANICAL BREAK-DOWN AND PARTS LIST 507 

5-2-1 FDD ^^■^ 

5-2-2 Screw, Washer ^-^^ 

5-3 PCBA PARTS LIST 

5-3-1 PCBA MFD Control ^-^^ 

5-3-2 PCBA Front OPT - 

5-4 SCHEMATIC DIAGRAMS AND PARTS LOCATION ^21 



- V - 



SECTION 3 



THEORY OF OPERATION 



- 300 - 



3-1. CONSTRUCTION AND FUNCTION 
3-1-1. General Block Diagram 



READ DATA 



SIDE^ONE^ 
SELECT 

WRITE DATA 



DRIVE 

SELECT 0^3 

WRITE GATE 
MOTOR ON 
STEP 

DIRECTION 
SELECT 

IN USE or 
HEAD LOAD 

TRACK 00 
INDEX 

READY 

WRITE 
PROTECT 

+12V,+5V,0V 



Read 
write 
circuit 



Control 
circuit 



Indi- 
cator 



-File protect sensor 
-File protect sensor LED 
-Disk 



sensor 
sensor LED 

motor 



Servo 
circuit 



Magnetic 
Head load solenoid 
Track 00 sensor 
Stepping motor 




(Fig. 301) General block diagram 



- 301 - 



3-1-2. Mechanical Section 



Since the disk is a flexible recording media made of mylar film base 
and data interchangeability between disks and FDDs is required, the 
mechanical section of the FDD uses precision parts and it is also 
assembled with high precision. For this reason, only trained technicians 
can handle the internal mechanism. Never apply excessive impact nor 
drop the FDD down on the desk. 

The mechanical section is constructed with frame, door mechanism, disk 
clamp mechanism, disk rotation mechanism, magnetic head and carriage, 
head load mechanism (or CSS mechanism) , head seek mechanism, various 
detection mechanisms, etc. 

(1) Frame 

The main structure for mounting the various mechanisms and printed 
circuit boards. The frame is made of aluminum die cast to maintain 
the stability of the FDD in strength, precision, durability, and 
expansion coefficient. 

(2) Door mechanism and disk clamp mechanism 

The door mechanism is constructed with the main parts of set arm which 
forms the structure for installing the disk on the spindle; other parts 
of front lever, clamp arm, etc. The set arm is sttached to the rear 
of the frame with leaf springs and on the tip of the set. arm a collet, 
which forms the disk clamp mechanism, is attached. 

When a disk is inserted and the door is closed, the tip of the collet 
is inserted in the central window of the disk and the window area is 
depressed to the spindle so that the center of the disk is clamped in 
the correct position along the outer circumference of the collet. 

(3) Disk rotation mechanism 



- 302 - 



The disk rotation mechanism comprises DD motor Ass'y which includes 
spindle . 

The DD motor is an outor-rotor type DC brushless motor which has the 
long life of 30,000 hours or more in continuous rotation. 
The rotational speed is SOOrpm (or 360rpm) and maintains stable rotat- 
ional speed against load variations and environmental changes. This is 
achieved by a feedback signal from the internal AC tachometer. 
The precisely combined collet and spindle are attached at the correct 
angle to maintain the center position correctly without damaging the 
center hole of the disk and so as to make the head be in contact with 
disk at the correct angle. 

(4) Magnetic head and carriage 



Read/write gap-^ i.rase cores 

(Fig. 302) External view of magnetic head core 

For single sided FDDs, the external view of the magnetic head is button 
shaped and it is mounted on the carriage so that it is in contact 
with the SIDE (the buttom side when the FDD is placed horizontally) 
head window area of the disk. 

For double sided FDDs, both the SIDE 1 head and the SIDE head are 
special flat type supported with the gimballed mechanisms. The two 
magnetic heads are mounted accross the disk on one carriage. 
In both types of head, the surface is designed for minimum disk wear 
and maximum read output. The head itself is a long life type for 
improved head wear. Each head. is constructed with a read/write- gap 
used for data reading and data, writing jind two erase gaps to erase the 
recorded track edge immediately after the recording (tunnel erase) . 
The magnetic head and the carriage on which the head is mounted form the 




Erase gaps 



Read/write core 



- 303 - 



core section of the FDD and is specially assembled with high preci 
(5) Head load mechanism or CSS mechanism 



sion. 



The head load mechanism is used for models with head load solenoid and 
the CSS mechanism is used for double sided CSS model without head load 
solenoid. Neither of these mechanisms are used for single sided CSS 
model. 



The head load mechanism functions to make the head in contact with the 
disk when only required so as to reduce disk and magnetic head wear. 
This mechanism is constructed with head load solenoid, arm lifter, etc. 
For a single sided FDD, the head pad attached to the pad arm of the head 
carriage is depressed against the SIDE 1 of the disk with appropriate 
pressure and the disk is held with head and head pad. For a double 
sided FDD, the SIDE 1 head is depressed with appropriate pressure 
instead of the head pad, as well as the single sided FDD. 

In the CSS model, the magnetic head is always in contact with a disk 
as far as the disk is installed. In order to elongate the disk and 
head lives, it is required to make the disk rotate only when it is 
necessary. The CSS mechanism (double sided) is constructed with a CSS 
Ass'y which is designed to protect the contact of SIDE and SIDE 1 
heads when the front lever is closed if a disk is not installed. For 
the purpose of protecting the head beeing cought and damaged by the 
head window edge during disk insertion and ejection, the head protector 
to lift up the jacket a little is equipped to the CSS Ass'y. The head 
protector is also used in the models with head load solenoid. 

(6) Head seek mechanism 



The head seek mechanism consists mainly of stepping motor with a capstan 
(pooly) , steel belt (band), guide shafts, and carriage. The carriage - 
is connected to the capstan of the stepping motor through the steel belt 



- 304 - 



and is slided along the guide shafts. 

The stepping motor rotates 2 steps (3.6*) for 48tpi and one step (1.8") 
for 95tpi per one track space. To improve the continuity of the 
head seek operation and precision of head positioning, hybrid type 
4-phase stepping motor is adopted- This special motor is driven in 
a unique manner which brought a success in reducing the head ratiation 
and to obtain a highly precise positioning. 

The parallelism and the distance between the shafts and the center 
line of the disk, and shaft and disk themselves are precisely machined. 
Also the thermal expansion of the frame, steel belt, carriage, etc. are 
taken into consideration in the process of design so that they are 
mutually offset with the expansion of the disk. 

(7) Detection mechanisms 

(a) File protect detection mechanism 

This mechanism is constructed with an LED and a photo-transistor to 
detect the existence of the write enable notch of the disk jacket. 
When a disk with the notch covered is installed and the light pass 
for detection is disturbed, no write or erase current will be supplied 
to the read/write and erase heads and the recorded information on the 
disk is protected from an erroneous input of a write command. 
The LED is mounted on the PCBA DD motor servo and the photo-transistor 
on the PCBA front OPT. 

(b) Track 00 detection mechanism 

This mechanism is constructed with a photo-interrupter for detecting 
the outermost track position (track 00) of the head and the track 00 
stopper which is attached to the rear side of the head carriage. 
Inside tracks from the track 00 on the disk are used. Even .if an 
erroneous step out command is input from the track 00 position, the 
command will be ignored by the internal circuit of the FDD. 



- 305 - 



If the head moves out from the track 00 by some reason (such as 
impact during transportation) , the head carriage strikes the track 00 
stopper to protect the head from moving out of the returnable range 
at a next power on. 

When step-in commands are input from the innermost track, the head 
seeks toward inward and stops with an appropriate space left against 
the head window edge of the disk. In order to recalibrate the track 
from this position (returning operation to the track 00) , it is 
required to input the step-out commands with several additional steps 
to the maximum track number. 

Index detection mechanism 

LED and photo- trans is tor for the detection of the index hole are 
located at the index window area of the disk jacket. 

The LED is mounted on the PCBA DD motor servo and the photo- transistor 
on the PCBA front OPT. The index hole will be detected along the 
rotation of the disk. 



- 306 - 



3-2. CIRCUIT DESCRIPTIONS 



The electronics of the FDD is constructed with three sections which are 
read write circuit, control circuit, and searvo circuit- Read write 
circuit and control circuit are mounted on the PCBA MFD control, and servo 
circuit is on the PCBA DD motor servo. 

3-2-1. Read Write Circuit 

The read write circuit is constructed with read circuit, write circuit, 
and low voltage sensor. They are mostly packed in a read write LSI 
(bipolar) . 

Fig. 303 shows the block diagram. 



- 307 - 



o 

00 



SIDE 




Read write coil 
Erase coil 

Common (center tap) 



Low pass 
filter 



TP7 



Diode 
switch 



SIDE 1 



Read write head 



AO 



AI 



AI 



Pre- 
amp 



5 



Differentiation 
amp. 



TPS TP9#— 

AO cY 



Read write LSI 
(U9) 



TPIO 



CI 



WO 



Peak 
detector 



Time 
domain 
filter 



RD 



WD 



Write 




Data 




Erase 




driver 




latch 




driver 





EO 



Write power 
gate 



COM 

EG 0,1 



WG 



iTP2 



T 



!TP5 



Low 
voltage 
sensor 



LVS 



SO 



Output 
driver 



•READ DATA 



M 

t-3 
W 

D 
> 



0) 

rt 

fD 



2 
n 

rt- 

o» 
rt 

ft) 



H 

o 
td 

o 
z 
w 

w 



(Fig. 303) Read write 



circuit 



block 



diagram 



Read circuit 



The read circuit consists of pre-amplif ier , low pass filter, differenti- 
ation amplifier, peak detector, time domain filter and read gate 
(output driver) 

In read operation, the minute voltage induced by the read/write head is 
amplified about 30dB by the pre-amplif ier which is constructed with a 
video band differential amplifier. Undesirable high frequency 
noise is eliminated by the low pass filter (L2,L3,C28,etc. ) and the 
read signal is supplied to the differentiation amplifier (Ql,Q2,Ll,C20, 
etc. ) 

The differentiation amplifier phase- shifts the peak position of the 
reproduced waveform to the zero cross point, and at the same time, 
further amplifies the signal about 20dB with the most appropriate 
equalization. The peak detector which is constmcted with a comparator 
converts the differentiated output into a square wave. 
The time domain filter eliminates a virtual pulse caus.ed by the saddle 
in the low frequency area (IF area, 62 . 5KHz , approx . for models A F, 
and 125KHZ for model G) at outer tracks. The time domain filter is 
constructed with two edge detectors, 2.4ysec, delay single shot (LSI 
pin 7, RA9, C23) , data latch, and lysec data single shot (LSI pins 8 
and 9, RA9,C24) 

Then the signal is output from the FDD through the read gate, U7 (pins 
4 6 , output driver) 



- 309 - 



Magnetization 
on disk. 



Pre- amp . output 
(TP7) 



Pre- amp . output 
(TP 8) 



Differentiation 
amp . output 
(TP9) 



Differentiation 
amp . output 
(TPIO) 



Peak detector 
output in U9 




5V 

approx . 



5V 

approx. 



5 V, approx. 



57 , approx . 



(Fig. 304) Read amp. and peak detector waveforms 



- 310 - 



-virtual pulse (drop-in) 



Peak detector 
output in U9 



Edge detector #1 
output in U9 



2-4vis delay S.S. 
Q output in U9 



Data latch output 
in U9 



Edge detector #2 
output in U9 

Read data (RD) 
(TPS) 



READ DATA 
(U7,pin 6) 



Jl 



Jl 



-2. 4ys,approx. 



1 — r 
I I 
I I 



n 



-lVis,approx. 



il 



n 



1 r 
u 



JLJLJl 



JLJLJl 



1 I — I ! — I r 
u u u 



il 



n 



u 



(Fig. 305) Time domain filter and read gate waveforms 



- 311 - 



(2) Write circuit 



The write circuit consists of write power gate (with side selector) , 
select gate, data latch, write driver, and erase driver. 
The write power gate output (COMO or COMl) becomes high voltage when 
the write gate signal or the erase gate signal is TRUE (HIGH level) . 
These signals are generated by the write/ erase gate in the control 
circuit when all of the following three conditions are satisfied. 

(a) The file protect sensor detects the notch of the disk jacket (write 
enable condition) . 

(b) The WRITE GATE input signal is TRUE. 

(c) MX strap is on or the DRIVE SELECT signal is TRUE (LOW). 



The write power gate output is supplied to the common terminal of the 
head through the diode switch. Table 301 shows the output voltage of 
the write power gate in various operations. 



Conditions 


Write power gate output voltage 


COM (for Side 0) 


COM 1 (for Side 1) 


Side write operation 


High 


Low 


Side 1 write operation 


Low 


High 


Side read operation 


Middle 


Low 


Side 1 read operation 


Low 


Middle 



High: 10.5V,approx. Middle: 4V,approx. Low: OV,approx. 



(Table 301) Write power gate output voltage 

The erase gate signal is delayed appropriately against the write gate 
signal. Since the erase gap is about 0.85mm (FD-55A'^' F models) or 
0.585mm (FD-55G model) behind the read/write gap, it is necessary for 
the erase driver to delay the write gate signal so that the written 
data is completely trimmed by the erase head (tunnel erase) . The 



~ 312 - 



tunnel erase produces a guard band between the tracks preventing 
deterioration of the S/N ratio resulting from a off-track (positioning 
error) . It also ensures disk interchangeability . 



The WRITE DATA input pulse is latched by the data latch. And 
appropriate write current is supplied to the read/write head by turning 
on and off the two write drivers alternately. When the write driver is 
active, no read data pulse is generated by the read circuit. 



WRITE GATE input 



Write gate (WG) 
(U9,pin 16) 

Erase gate (EG) 
(TP2) 

SIDE ONE SELECT 




Erase off 
delay 



WRITE DATA 



ir~irirTinr^inr~ii 



Data latch output 



Write driver output 
(U9,pin 21 or 22) 



Write current 



Magnetization on 
disk 








V 



j\r\r\i 



VM///////r 



Magnetized 
previously 



(Fig. 306) Write circuit waveforms 



- 313 - 



Low voltage sensor 

The low voltage sensor is equipped to protect the FDD from erroneous 
operation due to the internal circuits construction of the FDD during 
unstable state of the supplied voltage such as at power on or off. 
The output of this sensor is ANDed to all the output drivers of the FDD. 
Therefore, in the unstable state of +5V and +12V power when the internal 
logic of the FDD does not function normally, it protects erroneous 
operations of write driver and erase driver, erroneous signal output 
to the host system, and etc. 



Power on 



Power off 



+5V power 



Low voltage sensor 

output 

(U9,pin 17) 



3 . 4'v>4 . 4V 




Note: Dotted line shows the LVS input pin 34 of U6, control LSI. 
(Fig. 307) Low voltage sensor waveforms 



- 314 - 



3-2-2. Control Circuit 



The control circuit consists of gates, detectors, and the stepping 
motor control circuit. The gates are drive select gate to determine 
the drive select condition, head load gate to determine the head load 
condition (with head load solenoid models) , spindle motor gate to 
determine the rotational condition of the spindle motor, write/erase 
gate to control the actual write operation, etc. The detectors are 
index/sector detector, track 00 detector, file protect detector, and 
ready detector. The former three detectors (photo-transistors) are 
mounted on the PCBA front OPT and the transport frame. And 
the other circuits are mounted on the PCBA MFD control (mostly packed 
in a control LSI (CMOS)). 
Fig. 308 shows the block diagram. 



- 315 - 



DRIVE 

SELECT 

0'V3 



IN USE or 



HEAD LOAD 




MOTOR 01 



Drive 
select 
gate 



WRITE GATE 



DIRECTION 
SELECT 

STEP 



LVS 



Spindle motor 
gate 



Indicator 
gate 



Head load 
gate 



Write/erase 
gate 



Stepping motor 

control 
circuit 



Over 
drive 
circuit 



Solenoid 
driver 



1 



TP2 



Over 

drive 
circuit 



Stepping 
motor 

driver 



i 



TPS 
TP 6 

1 



TP 4 



TRACK 00 
INDEX 

READY 

WRITE 

PROTECT 



-Spindle motor 



^ront bezel 
indicator 



Head load 
solenoid 



Erase gate 
Write gate 



Stepping 
motor 



File protect detector 



I 



TPl 



Index detector 



I 



Track 00 detector 



(Fig. 308) Control circuit block diagraim 



- 316 - 



Drive select gate classifies the external input signals into several 
functions and transmits them into the control LSI . 

The selection of straps (short bars) determines the select condition 
of the drive, head load and spindle motor operating conditions, and 
turn-on condition of the front bezel indicator. Refer to items 1-11 
and 1-12 of the Specification as to the detailed function of each strap. 

The head load gate, adding the pre-ready condition to the selected head 
load command by the drive select gate, turns on the solenoid driver. 
The head load gate also triggers the internal over-drive timer 
constructed with a re-triggerable counter and maintains the over-drive 
circuit on for a determined period (26msec,approx. ) . During this period, 
+12V power is applied to the head load solenoid to execute the drawing 
action of the solenoid stably. 

To protect the head positioning error by the impact of the head loading, 
the stepping motor is also over-driven. After the completion of the 
over-driving, both the head load solenoid and the stepping motor are 
maintained by +5V power to minimize the power loss. 

The write/erase gate judges the FDD whether it can execute write 
operation or not and issues write gate and erase gate signals for the 
write circuit. A specified delay time is established in the erase 
gate signal by an internal counter (refer to Fig. 306) . 

The ready detector consists of speed detector, pre-ready latch, and 
ready latch. The output of the speed detector which is constructed 
with a re-triggerable counter becomes always TRUE (HIGH) when the 
rotational speed of an installed disk (soft sectored) is more than 
50%, approx. of the rated speed. The pre-ready latch detects the 
first index pulse (pre-ready condition) after the speed detector 
detects the 50% of the rated speed. The output of the ready latch 
becomes TRUE (HIGH) when the second index pulse after the 50% of the 
rated speed, then the READY condition is informed to the host system 
through the output driver, U2 (pin 1 3) . 



317 - 



Rotation starts 



Disk speed 



Index sensor output 
(TP4) 

Speed detector 
output in U6 



Pre-ready latch 
output in U6 

Ready latch output 
(U6,pin 12) 



READY signal 



n 



600msec , Max. 



SOOmsec ,Max. 



Constant speed 



il 



Pre-ready state 



Ready state 



Head load enable 
(with head load solenoid 
model) 



(Fig. 309) Ready detector waveforms 



Stepping motor control circuit is constructed with direction latch, 
internal step pulse generator, shift register, phase drive selector, 
overdrive timer, etc. 

Direction latch is a circuit to sample and hold the head seek 
direction designated by the DIRECTION SELECT signal at every input 
of the STEP pulses. 

The internal step pulse generator is constructed with a counter and 
a pulse generator- The counter is triggered at the trailing edge 
of the STEP input pulse, and the second internal step pulse is 
generated with a delay of 3msec, approx. from each STEP input pulse by 
the pulse generator. The internal step pulse generator functions only 
in a 48tpi FDD. It makes the stepping motor rotate for 2 steps (3.6") 
in response to one STEP input pulse. In a 96tpi FDD, the stepping 
motor rotates for one step (1.8' ) in response to one external STEP 
pulse. 



- 318 - 



Outputs of the direction latch and the internal step pulse generator 

are converted to the appropriate timing signals for uni-polar one-phase 
drive (partially 2-phase drive) of the 4-phase stepping motor. These 
phase drive signals are supplied to the stepping motor driver, U8 
(output pins 10'^' 13). In order to improve the torque margin in the 
seek operation, partially 2-phase drive period is provided by the 
phase drive selector only in the initial stage when the drive phase 
is changed. 

The output from the internal step pulse generator is also supplied to 
the over-drive timer constructed with a re-triggerable counter. During 
the active period of this timer (75msec ,approx. ) , +12V power is supplied 
to the stepping motor coils through the over-drive circuit (Q3) to 
produce enough torque required for the head seek and the settling 
operations. After the completion of the settling, only +5V power is 
supplied to the stepping motor through the diode, CR3, which minimize 
the power loss by supplying only the required torque for the holding 
of the stop position. By the above consideration, heat radiation from 
the motor is depressed to the minimum level and the stepping motor 
power consumption of 0.25W, approx. at the stop condition is achieved. 



- 319 - 



DIRECTION SELECT 



Step-out 



Step-in 



STEP 

Direction latch output 
in U6 

48tpi FDD: 

Internal step pulse gen, 
.output in U6 

Overdrive timer output 
(U6,pin 19) 



Motor driver inputs 
PHASE A (U8,pin 4) 

PHASE B (U8,pin 5) 
(TP3) 

PHASE A (US, pin 6) 



PHASE B (US, pin 7) 



96tpi FDD: 

Internal step pulse gen 
output in U6 

Overdrive timer output 
(U6,pin 19) 

Motor driver inputs 
PHASE A (US, pin 4) 

PHASE B (U8,pin 5) 
(TP3) 

PHASE A (U8,pin 6) 

PHASE F (U8,pin 7) 




tl: Second step delay ( 3ms , approx . ) 

t2: Partial 2-phase magnetization ( . 6ms , approx . ) 



(Fig. 310) Stepping motor control circuit waveforms 



- 320 - 



3-2-3 . Servo Circuit 

The servo circuit aims to maintain the rotational speed of the spindle 
motor at 300rpm (or 360rpm) , and the circuit is mounted on the PCBA 
assembled with the spindle motor. 

Start and stop of the spindle motor (DD motor Ass'y) is controlled by 
the MOTOR ON signal supplied through the spindle motor gate in the 
control circuit. 

The spindle nKDtor is a long life DC brushless motor having 2-phase or 
3-phase coils and bi-polar drive system. The coils are driven by the 
exclusive drive IC. Energization and magnetized direction of the coils 
are controlled by the signal from the hall elements mounted on the PCBA 
around the rotor so that they are changed corresponding to the designated 
rotational direction. 

The rotational speed is maintained stably and precisely. The feedback 
signal from the AC tacho-meter in the rotor is converted into the drive 
voltage (F-V conversion) by servo IC, and supplied to the drive IC 
through the phase compensation circuit. 

Several manufacturers' spindle motors are used in FD-55 series for the 
stable supply of the motor. Though these motors are almost the same 
in the function and performance, they are different in external view 
because of a little difference in the servo circuit, etc. 



- 321 - 



3-3. FUNCTION OF TEST POINTS AND VARIABLE RESISTORS 



Fig. 311 shows the mounting position of the test points and variable 
resistors. 




G 10 9 8 7 
(OV) TP PCBA MFD control #B 




PCBA DD motor servo 



Notes: 1- Some versions or some revision numbers of the PCBA MFD control 
#B have not the variable resistor R5. 

2. Some types of DD motor Ass'y have not the variable resis'tor Rl. 
(Fig, 311) Location of test points and variable resistors' 



- 322 - 



3-3-1. Function of Test Points 



Twelve test points (two for ground) are equipped on the PCBA MFD 
control for the check and adjustment of the FDD. 

(1) TPl (Track 00 sensor) 

Test point to observe the output of the track 00 detection photo- 
transistor. 

The signal level at this TP is opposite to that of the TRACK 00 output 
signal. When the head is on track 00 or around track 00 position, TPl 
becomes HIGH level. 

The voltage of TPl should be more than 3V at track 00 and less than 0.5V 
at track 02 (48tpi) or track 04 (96tpi) . 



Note: The TRACK 00 output signal goes TRUE (LOW level) only when the 

phase A coil of the stepping motor is energized and the direction 
latch is set to the step-out direction (refer to Fig. 310). Therefore, 
the level change timing of the TRACK 00 signal is not consistent 
with that of the TPl signal. 

(2) TP 2 (ERASE gate) 

Test point to observe the output of the erase gate. 

When TP2 is HIGH level, erase current flows through the erase head. 

This TP is used for the check of the required delay time of the erase 



Track 02(04) and 

greater track 



TPl (Track 00 sensor) 




(Fig. 312) Typical waveform of TPl 



- 323 - 



gate signal against the WRITE GATE input signal. 



WRITE GATE input signal 
TP2 ( Erase gate ) 
















Off-delay 






On-delay 







(Fig. 313) Typical waveform of TP2 



Delay 


FD-55A % F 


FD-55G 


On-delay 


200 % 320ys 


175 'x. 210ys 


Off-delay 


860 950ys 


500 'V. 550ys 



(Table 302) Erase gate delay 



(3) TP3 (Phase B) 

Test point to observe the phase B magnetized period of the stepping 
motor. For the 48tpi FDD, it is also used for observing the delay 
time of the second step pulse which is produced automatically in the 
FDD- It is also used for all the FDDs, as the observation point of the 
partial 2-phase magnetization timing of the stepping motor. 

For the 48tpi FDD, the stepping motor rotates for 2 steps in response 
to one STEP input pulse. Therefore, TP3 goes HIGH level for a specified 
time when a step-out command from an even track or a step-in command 
from an odd track is executed. Refer to Fig. 310. 
For the 96tpi FDD, the stepping motor rotates only for 1 step in 
response to one STEP input pulse by which one track space is moved. 

TP3 maintains HIGH level when the head is on the l+4n(n=0,l,2, ) 

track (phase B magnetized) or for a specified time during step-in or 



- 324 - 



step-out operation from the above l+4n track. 



48tpi FDD: 

STEP input pulse 



TP3 (Phase B magnetized) ^^^^^ 



Second step delay 
{ 3ms , approx . ) 




— — Partial 2-phase magnetization 
( . 6ms , approx . ) 



tl+t2= 3.6±0.3ms 



96tpi FDD: 

STEP input pulse 



TP3 (Phase B magnetized) ^^^^^ 



Step pulse inteirval 




Partial 2-phase magnetization 
0.6±0.2ms 



t+t2=t+ ( . 6±0 . 2 ) ms 



(Fig. 314) Typical waveform of TP3 



(4) TP4 (Index) 



Test point to observe the output of the index detection photo- trans is tor 
after inverting the level by the Schmitt inverter. 

The signal level at this TP is opposite to that of the INDEX output 
signal. When the index hole or sector hole (hard sectored disk) is 
detected, HIGH going pulse is observed at TP4. The photo- transistor is 
mounted on the PCBA front OPT and the LED is mounted on the PCBA 
DD motor servo. 

The test point is used for the following purposes. 



- 325 - 



(a) Confirmation and adjustment of the disk rotational speed. Speed is 
adjusted by the variable resistor Rl on the PCBA DD motor servo. 



Note: Some types of DD motor Ass'y have not the variable resistor Rl 
for rotation speed adjustment. In such a DD motor Ass'y, no 
adjustment is required and the rotation speed is determined by an 
oscillation frequency of the ceramic oscillator mounted on the 
PCBA DD motor servo. 

(b) Confirmation and adjustment of the index burst timing. Burst timing 
is adjusted by the fixing screws of the PCBA front OPT. 



TP4 (Index) 



n 



n 



Index 
interval 



Pulse width 



(Fig. 315) Typical waveform of TP4 (Speed observation) 



Items 1 


FD-55A F 


FD-55G 


Index interval | 


200±3ms 


166.712. 5ms 


Pulse width 1 


2 'V' 5.5ms 


1 8ms 


Burst delay | 


200±200ys 


165±165us 



(Table 303) Index timing 



TP4 (Index) 
TP7 or 8 

(Pre-amp. output) 







1 

1 




— \ 


m 






Index burst delay 



(Fig. 316) Typical waveform of TP4 (Burst timing observation) 

" 326 - 



(5) TPS (Read data) 



Test point to observe the read data pulse. 

The signal level at this TP is opposite to that of the READ DATA output 
signal. 



TPS (Read data) 



Pulse width 



2F 



interval 



4/3F interval 



IF interval 



(Fig. 317) Typical waveform of TPS 



Fig. 317 shows the waveform at TPS in normal data read operation. 

In the FM method, 2F and IF intervals are observed, while 2F, 4/3F, and 

IF intervals are observed in the MFM method. 



Items 


FD-55A '^' F 


FD-S5G 


2F interval 


4ys, Norn. 


2y s , Nom . 


4/3F interval 


6ys, Nom. 


3ys, Nom. 


IF interval 


8ys, Nom. 


4y s , Nom . 


Pulse width 


liO.Sys 


O.S±0.2Sys 



(Tcible 304) Read data pulse timing 



(6) TP6 (File protect sensor) 



Test points to observe the output of the file protect detection photo- 
transistor. 

The signal level at this TP is opposite to that of the WRITE PROTECT 
output signal. When a disk with the masked write protect notch (write 



- 327 - 



operation cannot be done) is installed, TP6 becomes HIGH level. 
The voltage of TP6 should be more than 3V at masked notch and less 
than . 5V at open notch (write enable condition) - 



TP6(File protect sensor) 



3.0V,Min. 



0.5V, Max. 



Notch open 



Notch masked 



(Fig. 318) Typical waveform of TP6 



(7) TP7, TPS (Pre-amplifier) 

Test point to observe the read pre-amplifier output signals. 

The pre-amplifier has two outputs of the order of several dozen to 

several hundred mVp-p, and they differ in phase by 180* (opposite phase) . 

Both outputs are observed at TP7 and TPS respectively. 

For an accurate observation of the read waveforms, use two channels of 

an oscilloscope with one channel set to Invert mode and Add mode of 

both channels. Use G (OV) test point for the oscilloscope ground. 

TP7 and TPS are used for checking various characteristics of the 

read/write head and also for the check and adjustment of the head seek 

mechanism such as track alignment. 



TP7,TP8 
( Pre-amp . ) 




5V,approx. 



(Fig. 319) Typical waveform of TP7 and TPS 



(8) TP9, TPIO (Differentiation amplifier) 



- 328 - 



Test points to observe the differentiation amplifier output signals . 
Like the pre-amplif ier , the differentiation amplifier also has two 
outputs of the order of several hundred mVp-p to several to several 
Vp-p which differ in phase by 180** . Both outputs are observed at TP9 
and TP 10 respectively. 

For an accurate observation of the waveforms, use two channels of 
the oscilloscope with one channel set to Invert mode and Add mode 
of both channels. 

Use G (OV) test point for the oscilloscope ground. 

TP9 and TP 10 are used for checking the total operation of the read/write 
head and the read amplifier and for the check and adjustment of the head 
seek mechanism such as track alignment. 



TP9,TP10 
(Differentiation 
amp . ) 

(Fig. 320) Typical waveform of TP9 and TP 10 
(3) TP G (.OV), — PCBA MFD control, PCBA read write amp. 

TP G is equipped respectively for two test point blocks (TPl 6 and 
TP7 'x^ 10) . They are used as the ground terminals for measurement 
equipment. Be sure to use a small size clip to obtain a probe ground 
of the equipment. 




5V,approx. 



- 329 - 



3-3-2. Function of Variable Resistors 

On the PCBA MFD control and the PCBA DD motor servo, maximum two 
variable resistors are mounted. 

The PCBA MFD control of some PCBA versions and some revision numbers 
has not the variable resistor R5. Also some types of DD motor Ass'y 
have not the variable resistor Rl on the PCBA DD motor servo. 
However, there is interchangeability in function and performance 
between these PCBAs with the variable resistor and without the 
variable resistor as far as they have the same parts number (8 digits) 
and the same version number (2 digits). It is not necessary to identify 
one from another as the spare parts. 

The variable resistors are correctly adjusted before the shipment of 
the FDD and fundamentally they shall not be readjusted except for by 
a trained technicians . 

(1) Rl on PCBA DD motor servo (Disk rotational speed adjustment) 

Variable resistor for adjusting the rotational speed of the disk. 
It IS adjusted so that the index pulse interval at TP4 or at the INDEX 
output signal is 200msec±3msec for FD-55A 'x^ F and 166. 7ms ec± 2 . 5msec for 
FD-55G (see Fig. 315) . 

For the DD motor Ass'y without the variable resistor Rl, the rotation 
speed of the motor is fixed by the ceramic oscillator in the servo 
circuit and no adjustment is required. 

(2) R5 on PCBA MFD control (Read data asymmetry adjustment) 

Variable resistor for adjusting the asymmetry of the read data pulse. 
Some PCBAs have this variable resistor and others have fixed resistor 
instead of it. 

For a PCBA with the variable resistor, R5, write IF data and observe 
the pulse intervals at TPS or at the READ DATA output signal during- 
read operation. Then adjust the variable resistor so that the read 



- 330 - 



data asyiranetry in Fig. 321 takes the minimum value- For a double s 

j_ j_v - - t.-:^^ -, T +-^-»-r^^4-^»l -Fr^r- c n o H ^nt^ c;idf> 1 heads 

CUU, repeciL. UliXis vjpeiQi-J-i^ii aj.i.^J.i'.iS.-^-^j - 

obtain the minimum asymmetry for both sides. 



TPS (Read data) 





r 


IF interval ^ 


— Asymmetry 
2 

in 


1 


1 

Ji 


Asymmetry 



Trigger 



FD-55A F; 
FD-55G 



0-6iJS,Max, 
0. 3ps,Mcix. 



(Fig. 321) Read data asymmetry 



- 331 - 



SECTION 4 



MAINTENANCE 



- 4000 - 



4-1- GENERAL 



4-1-1. Periodic Maintenance 

The FDD is designed to be free from periodic maintenance such as 
replacement of parts, grease-up, etc. when it is operated at a normal 
operation duty. 

However, cleaning of the magnetic head using a cleaning disk is 
recommended since it is effective to improve the reliability of the data. 
If some of the parts in the FDD are operated at a specially heavy duty 
condition, or if the _FDD is operated over 5 years, it is recommended 
to replace the wear parts according to Table 403. 



Periodic maintenance items 


Recommended 
cycle 


Required 
time 


Referred 
items 


Cleaning of magnetic head 


Refer to 4-3-1 
and 4-3-2 


5 min. 


4-3-1 


Replacement of wear parts 


Refer to 4-1-3 and 4-5. 



(Table 401) Periodic maintenance items 



- 4001 - 



4-1-2, Check and Adjustment 

Table 402 shows all of the check and adjustment items. 
Following items do not require periodic maintenance- Check and 
adjustment should be done when required during replacement of the 
maintenance parts or during trouble shooting referring to items 4-2 
and 4-3. 

The nimbered procedure in Table 402 shows a typical procedure of the 
general check and adjustment all over the FDD. 



- 4002 - 



steps 


Check and adjustment items 


Required time i Referred items 


1 


Adjustment of set ann 1 
position 1 


5 minutes 


4-4-1 


2 


Adjustment of clamp arm 

position 1 


5 minutes 


4-4-2 


3 


Adjustment of front lever | 


5 minutes 


4-4-3 


A 


Adjustment of arm lifter 

(Model with head load solenoid only) 


5 minutes 


4-4-4 


5 


Check of CSS Ass'y 
(Double sided CSS model only) 


5 minutes 


4-4-5 


6 


Check of file protect sensor 


5 minutes 


4-4-6 


7 


Check and adjustment of disk 
rotational speed 


5 minutes 


4-4-7 


8 


Check of erase gate delay 


5 minutes 


4-4-8 


9 


Check and adjustment of head touch 


5 minutes 


4-4-9 


10 


Check and adjustment of asymmetry 


5 minutes 


4-4-10 


11 


Check of read level 


5 minutes 


4-4-11 


12 


Check of resolution 


5 minutes 


4-4-12 


13 


Check and adjustment of track 
alignment 


10 minutes 


4_4_13 


T A 
14 


V^neCK anci aCljUoi— u-itiiii- vJJL \-^a.^r\. \J\J 

sensor 


5 minutes 


4-4-14 


15 


Check and adjustment of track 00 
stopper 


5 minutes 


4-4-15 


15 


Check and adjustment of index 
burst timing 


5 minutes 


4-4-16 



(Table 402) Check and adjustment items 



- 4003 - 



4-1-3. Maintenance Parts Replacement 



It is recommended to replace the wear parts periodically if the FDD 
is operated at a specially heavy duty condition or if it is operated 
over five years. Periodic replacement is not required for the parts 
if the FDD is operated at a normal operation duty. 

Table 403 shows all of the maintenance parts- Replace the wear parts 
according to the recommended replacement cycle. Periodic replacement 
is not required for parts without a recommended replacement cycle. 
The replacement of the parts should be done according to each referred 
item in Table 403. 

Notes for Table 403: 

(1) If two parts nxambers are listed for one part, either of the two may be 
used. Fundamentally, parts without brackets are used at the shipment 
though parts with brackets may be used since they are interchangeable 
as spare parts. 

(2) Since the parts number versions of the PC3A MFD control #B and the PCBA 
front OPT vary depending on some factors such as signal interface 
condition, be sure to confirm the version by checking the name plate 

on the actual printed circuit board. 

(3) The head carriage Ass'y are used always in pair with two guide shafts. 
The head carriage Ass'y represented by listed parts number in Table 403 
includes these guide shafts which parts number is different from that 
of a head carriage Ass'y itself without these guide shafts. 

(4) The listed parts numbers of the front bezel Ass'y and the front lever 
Ass'y are those of standard color (black). For designating other 
color, use the corresponding parts number. 

(.5) The parts number version of the front bezel Ass'y and the front lever 



- 4004 - 



Ass'y is -50 which is different from the version (-00) of the 
conventional FD-55 series listed in the Maintenance Manual. This 
difference indicates that the material is changed from ABS to PPHOX 
(Zyron) . Both of the assemblies are interchangeable between -50 and -00. 

(6) The head load solenoid Ass'y applies only to the models with head 
load solenoid. The CSS Ass'y applies only to the do\ible sided models 
without head load solenoid. The head load solenoid Ass'y and the 
CSS Ass'y will never be installed together in a model. 

(7) The parts niimber of the head load solenoid Ass'y is different from that 
(P/N 17766799-01) of the conventional FD-55 series listed in the 
Maintenance Manual. This is because of partial improvement of the 
Ass'y. Both new and old assemblies are interchangeable each other. 
The head load solenoid Ass'y of the listed parts numiser in this manual 
need not adjustment of head' protector . Therefore, the explanation 
for it is deleted from this manual. 

(8) The parts number version of the head pad for single sided models is -01 
which is different from the version (-00) of conventional FD-55 series 
listed in the Maintenance Manual. This is because that the diameter 

of the pad is decreased a little for improving the function. Be sure 
to note that the improved smaller pad has not interchangeability with 
the old type when it is attached to the pad arm (refer to item 4-5-11) . 

(9) Periodic replacement is not required for parts without a recommended 
replacement cycle*^ Replace the parts when required such as during 
repair. 

(10) If two recommended cycles are listed, the cycle which the parts reach 
first should have priority. 

(11) The required time for replacement includes the time for basic check 
and adjustment after the replacement. 



- 4005 - 



(Table 403-1) FD-55A (Single sided, 48tpi) Maintenance parts list 



Maintenance parts 


Replacement 


Parts name 


Description 


Parts No. 


Replacement cycle 


Required time 


Referred items 


Head carriage Ass'y 


Note (3) 


17966940-00 


7,000 head load & motor 
7 

on hrs.or 1x10 seeks 


45 min. 


4-5-1 


Stepping motor Ass'y 


Note (1) 


14769070-50 
or (-00) 


-J 

1x10 seeks 


30 min. 


4-5-2 


Steel belt 




16792265-00 


Replace with stepping 
motor Ass ' y 




4-5-2 


Belt spring 




16392008-00 


- 


4-5-2 


DD motor Ass ' y 
(Spindle motor) 


Note (1) 


14733730-10 
or (-00) 


30,000 motor on hrs. 


20 min. 


4-5-3 


Collet Ass'y 




17966793-00 


5 

3x10 clamps 


15 min. 


4-5-4 


Head load solenoid Ass * y 


Note (6) ,Note (7) 


17966859-01 


7 

1x10 head loads 


15 min. 


4-5-5 


Track 00 sensor Ass'y 




17966805-00 




10 min. 


4-5-6 


PCBA MFD control ttB 


Note (2)- 


15532001-XX 
1 


- 


30 min. 


4-5-7 


PCBA front OPT 


Note (2)- 


15531990-XX 


- 


10 min. 


4-5-8 


^ront bezel Ass'y 


Note (4) , Note (5) 


17966807-50 




10 min. 


4-5-9 


Front lever Ass'y 


Note (4) ,Note (5) 


17966808-50 




5 min. 


4-5-10 


Pad (Head pad) 


Note (8) 


16786634-01 


3,000 head load & motor 
on hrs. 


10 min. 


4-5-11 















(Table 403-2) FD-55B (Double sided, 48tpi) Maintenance parts list 



Maintenance parts 


Replacement 


Parts name 


Description 


Parts No. 


Replacement cycle 


Required time 


Referred items 


Head carriage Ass'y 


Note (3) 


17966941-00 


7,000 head load & motor 
on hrs.or 1x10' seeks 


45 min. 


4-5-1 


Stepping motor Ass'y 


Note (1) 


14769070-50 
or (-00) 


1x10^ seeks 


30 min. 


4-5-2 


Steel belt 




16792265-00 


Replace with stepping 
motor Ass ' y 


- 


4-5-2 


Belt spring 




16392008-00 


- 


4-5-2 


DD motor Ass'y 
(Spindle motor) 


Note (1) 


14733730-10 
or (-00) 


30,000 motor on hrs. 


20 min. 


4-5-3 


Collet Ass'y 




17966793-00 


3x10^ clamps 


15 min. 


4-5-4 


Head load solenoid Ass'y 


Note (6) ,Note (7) 


17966859-01 


1x10^ head loads 


15 min. 


4-5-5 


Track 00 sensor Ass'y 




17966805-00 




10 min. 


4-5-6 


PCBA MFD control ttB 


Note (2) 


15532001-XX 




30 min. 


4-5-7 


PCBA front OPT 


Note (2) 


15531990-XX 




10 min. 


4-5-8 


Front bezel Ass'y 


Note (4) ,Note (5) 


17966807-50 




10 min. 


4-5-9 


Front lever Ass'y 


Note (4) ,Note (5) 


17966808-50 




5 min. 


4-5-10 


CSS Ass'y 


Note (6) 


17966900-00 


6x10^ clamps 


10 min. 


4-5-12 















(Table 403-3) iJ'D-SSE (Single sided, 96tpi) Maintenance parts list 



Maintenance parts | Replacement 



Parts name 


Description 


Parts No. | Replacement cycle 


Required time 


Referred items 


Head carriage Ass'y 


Note (3) 


17966942-00 1 7,000 head load & motor 
1 on hrs.or IxlO'' seeks 


45 min. 


4-5-1 


Stepping motor Ass'y 




14769070-00 | Ixio"^ seeks 


30 min. 


4-5-2 


bueei oeit 




16792265-00 


Replace with stepping 




4-5-2 


Belt spring 




16392008-00 


motor Ass ' y 


- 


4-5-2 


DD motor Ass'y 
(Spindle motor) 




14733730-00 


30,000 motor on hrs. 
., 


20 min. 


4-5-3 


Collet Ass'y 




17966793-00 


3x10^ clamps 


15 min. 


4-5-4 


Head load solenoid Ass ' y 


Note (6), Note (7) 


17966859-01 


7 

1x10 head loads 


15 min. 


4-5-5 


Track 00 sensor Ass'y 




17966805-00 




10 min. 


4-5-6 


PCBA MFD control #B 


Note (2)- 


15532Q01-XX. 




30 min. 


4-5-7 


PCBA front OPT 


Note (2)- 


15531990~XX 




10 min. 


4-5-8 


Front bezel Ass'y 


Note (4) ,Note (5) 


17966807-50 




10 min. 


4-5-9 


Front lever Ass'y 


Note (4) Note (5) 


17966808-50 




5 min . 


fl— D— X U 


Pad (Head pad) 


Note (8) 


16786634-01 


3,000 head load & motor 
on hrs. 


10 min. 


4-5-11 















(Table 403-4) FD-55F (Double sided, 96tpi) Maintenance parts list 



Maintenance parts 


Replac 


;ement 




Parts name 


Description 


Parts No. 


Replacement cycle 


Required time 


Referred items 


Head carriage Ass'y 


Note (3) 


17966944-00 


7,000 head load & motor 
on hrs.or 1x10^ seeks 


45 min. 


4-5-1 


Stepping motor Ass'y 




14769070-00 


7 

1x10 seeks 


30 min. 


4-5-2 


Steel belt 




16792265-00 


Replace with stepping 
motor Ass'y 




4-5-2 


Belt spring 




16392008-00 




4-5-2 


DD motor Ass'y 
(Spindle motor) 




14733730-00 


30,000 motor on hrs. 


Z\j mxn. 


H J J 


Collet Ass'y 




17966793-00 


3x10^ clamps 


15 min. 


4-5-4 


Head load solenoid Ass'y 


Note (6) ,Note (7) 


17966859-01 


1x10^ head loads 


15 min. 


4-5-5 


Track 00 sensor Ass'y 




17966805-00 




10 min . 


H. -J D 


PCBA MFD control ttB 


Note (2)- 


15532001-XX 




30 min. 


4-5-7 


nr'iaiv ■f*-v-/-v OPT* 
Pt^iSA rxont \Jtr X 


Note (2)- 


15531990-XX 


- 


10 min. 


4-5-8 


Front bezel Ass'y 


Note (4) ,Note (5) 


17966807-50 




10 min. 




Front lever Ass'y 


Note (4), Note (5) 


17966808-50 




5 min. 


4-5-10 


CSS Ass'y 


Note (6) 


17966900-00 


6x10^ clamps 


10 min. 


4-5-12 















-5) FD-55G (Double sided, High density, 96tpi) Maintenance parts list 



Mainte 


nance parts 


Replacement 


Parts name 


Description 


Parts No. 


Replacement cycle 


Required time 


Referred items 


Head carriage Ass'y 


Note (3) 


17966943-00 


7,000 head load & motor 
on hrs.or 1x10'' seeks 


45 min. 


4-5-1 


Stepping motor Ass'y 




14769070-00 


1x10' seeks 


30 min. 


4-5-2 


Steel belt 




15792265-00 


Replace with stepping 
motor Ass ' y 




4-5-2 


Belt spring 




16392008-00 




4-5-2 


DD motor Ass'y 
(Spindle motor) 




14733730-50 


30,000 motor on hrs. 


20 min. 


4-5-3 


Collet Ass'y 




17966793-00 


3x10^ clamps 


15 min. 


4-5-4 




Note (6), Note (7) 


17966859-01 


1x10^ head loads 


15 min. 


4-5-5 


Track 00 Rpncsnr Acsg*\7 




17966805-00 


- 


10 min. 


4-5-6 




Note (2)- 


15532001-XX 




30 min 

*J \J 111 X J 1 . 


1— D— / 


PPBA frnnt- HPT 


Note (2)- 


15531990-XX 


- 


10 min. 


4-5-8 


Front bezel Ass'y 


Note (4) ,Note (5) 


17966807-50 




10 min. 


4-5-9 


Front lever Ass'y 


Note (4), Note (5) 


17966808-50 




5 mm. 


4-D-lO 


CSS Ass'y 


Note (6) 


17966900-00 


6x10^ clamps 


10 min. 


4-5-12 















4-1-4. Maintenance Jigs and Tools 

The following are the jigs and tools required for adequate maintenance 
of the FDD. 

(1) Equipment 

(A) When Simulator KA (off-line exerciser, abbreviated to SKA) is used: 

(a) Two different models of SKA are used for the maintenance of FD-55A 
through F, and for FD-55G. For FD-55G, designate SKA(-G) . 

The following accessories are necessary for operating the SKA (the 
accessories are supplied with the SKA) . 

i) SKA/FFD interface cable (-00) 

ii) Check cable #1 (for observation of control signals) 

iii) Check cable #2 (for cbser^/ation of read aiap. output signals) 

iv) SKA/FDD power cable 

(b) Oscilloscope (two channel) 

(c) DC power supply (+12V, 1.2A and +5V, 2A) or SKA power supply. 
The following accessory is required for the power supply (The 
accessory is supplied with the SKA power supply) . 

i) Power cable (4P) 

(d) Thermometer and hygrometer 

(B) When SKA is not used: 

(a) FDD controller and DC power supply (user's system) 

(b) Oscilloscope (two channel) 

(c) Frequency counter 



- 4011 - 



(d) Digital volt meter 

(e) DC clip-on ammeter 

(f ) Thermometer and hygrometer 

(2) Tools 

(a) Cross-point screwdrivers, M2.6 and M3 

(b) Common screwdriver, small size 

(c) Hexagon wrench key, 1.5mm 

(d) A pair of tweezers 

(e) Round nose pliers 

(f) Cutting pliers 

(g) Solder and soldering iron 

(h) Cutter knife 

(3) Special jigs 

(a) Max. media jig (Jig c, P/N 1789Q746-Q0) 

(b) Alignment adjustment jig (P/N 17851100-OOi 

(4) Disks 

(a) Work disk (commercially available disk) 

(b) Cleaning disk (commercially available cleaning disk) 

i) Single sided type 
ii) Double sided type 

(c) Alignment disk (CE disk) 

i) Single sided, 48tpi type (P/N 14900016-20) 
ii) Double sided, 48tpi type (P/N 14900016-21) 
iii) Single sided, 96/lOOtpi type (P/N 14900016-23) 



- 4012 - 



) Double sided, 96/lOOtpi type (P/N 14900016-24) 



(d) Level disk (P/N 14900015-00) 
(5) Other articles used during maintenance 

(a) Absolute alcohol (Ethanol) 

(b) Cotton swab or gauze 

(c) Locking paint (3 Bond, 1401B) 

(d) Screws and washers (Refer to item 5-2-2) 

Note: Be sure to use well calibrated equipment and disks. 



- 4013 - 



2, PRECAUTIONS 

2-1. Torque Applied to Screws and Locking Paint 

The following torque should be applied to screws, unless otherwi 
specified. 



Size of screws 


Torque 


M2 


2kg -cm 


M2.6 


4 . 5kg • cm 


M3 


5kg • cm 


M3 set screw 


4 . 5kg . cm 


M3 plastic screw 


1 . 5kg , cm 



(Table 404) Torque applied to screws 



For tightening or loosening M3 set screws for adjustment and parts 
replacement^ the following procedure should be followed. 

(1) For adjustment, remove out the set screw and also remove the locking 
paint which had applied to the screw itself and around it. 

(2) Apply fresh locking paint to the first three threads of the set screw 
with some narrow object such as a pair of tweezers. 

(3) Adjust or tighten the set screw with the* specif ied torque. 

For other screws than set screws, apply a drop of locking paint to the 
designated points after tightening them. 



- 4014 - 



4-2-2. Handling of Connectors 

(1) Types of connectors 

The following connectors are used for the FDD. 

(a) Jl: Interface connector 

(b) J2 : Power connector 

(c) J3: IC socket for terminator (resistor network) 

(d) J4: Head load solenoid & track 00 connector 

(e) J5: PCBA front OPT connector 

(f) J6: Stepping motor connector 

(g) J7: Spindle motor (DD motor Ass'y) connector 

(h) J8: (Option) Disk sensor connector 

(i) J9: Head connector 

(j) JIO: (Option) 1/1 size front bezel indicator connector 

(k) Jll: (Option) Door close switch connector or HD sensor connector 

(1) J12: (Option) PCBA VFO OPT connector 

(m) J13: (Option) Door lock solenoid connector 

(2) Connection and disconnection of the connectors 

Be sure to turn the power off before connecting and disconnecting the 
connectors. Connection or disconnection should be done straightly an( 
correctly without applying excessive force to the cables and the post 
pins. 

C3) Precautions for handling the white connectors (J6, Jl , Jll, J13) 
Ca) Disconnection of the connector 

As shown in Fig. 402, carefully pull up the edges of the upper 
protruding area of the connector little by little with the finger 
nails or with a screwdriver. 



- 4015 - 




File protect sensor 
PCBA front OPT 



□0- 




Index sensor 
9 (Option) 
10 (Option) 



J4 

J12 (Option) 

J9 

J5 



Top view of the FDD 



DD motor Ass 'y (Spindle motor) 




J4 

J12 (Option) 



PCBA MFD control #B 



(Fig. 401) Types of connectors 



- 4016 - 



Connector Jll (option) is installed upright on the PCB. Though the 

q£ Jll is little different from the connector below in the 
figure, pull up the edges of the upper protruding area in the same 
manner. 



Cable 




Pin numbers 



(pig. 402) Disconnection of white connector 

(b) Connection of the connector 

Push the connector into the post pin on the PCBA with the housing 
clamper up. 

For the connector Jll (option) , bring the hole of the pin onto the 
post pin position and push it. It will not be pushed in an opposite 
location . 

(c) Removal of the pin (for reference) 
Refer to Fig. 403. 

Depressing the stopper of the pin lightly with.a narrow object such 
as a pair of tweezers, pull the cable in the direction indicated by 
the arrow, 

(d) Insertion of the pin (for reference) 

Before insertion, check the following three points. 



i) Confirm that the sheath and the core of the cable are securely 
clamped. 

- 4017 - 




Housing clamper 



(Fig. 403) Sectional view of white connectors 

ii) Confirm that the stopper is lifted as in Fig. 403 and it inhibits 
accidental removal, 
iii) No tarnish or contamination should be on the contact area of the 
pin or the PCB side post pin. If there is, r^iove it. 

Contact failure may happen if any of these three points is not 

satisfied. 

When you insert the pin, it should be so inserted that the stopper 
faces the opening side of the housing. 

After the insertion, check the connection by pulling the cable lightly. 
Precautions for handling the black connectors (J4, J5, J9, JIO, Jll) 
a) Disconnection of the connector 

i) Pull out J4 connector (head load solenoid and track 00 connector) 
slowly holding the cable with a pair of tweezers or a round nose 
pliers carefully, 
ii) For pulling out J5 (PCBA front OPT connector) and J9 (head 

connector) , remove the screw fixing the cord guide (see Fig. 501, 
No.l) and pull the connector holding the cable and housing slowly. 
Be sure not to apply tension to the fine cables of the J9 (head 
connector) . 



- 4018 - 



iii) For JIO (option) and J12 (option) , pull out slowly in the same 
manner as in item i) and ii) . 

(b) Connection of the connector 

Make the polarizing key position of the housing correspond with the 
lack of the post pin, and push the housing carefully with the 
fingers. 

(c) Removal of the pin 

Lifting up the stopper of the housing with a narrow object such as 
cutter knife, pull the cable with a pair of tweezers in the direction 
indicated by the arrow. Refer to Fig. 404. 




(Fig. 404) Sectional view of black connectors 
(d) Insertion of the pin 

Before insertion, check the pins according to item (3)-(d), i) through 
iii) . 

When you insert the pin, it should be so inserted that the projection 
side faces the stopper of the housing. After the insertion, pull the 
cable with a pair of tweezers softly in order to confirm whether it 
is securely connected. 



- 4019 - 



4-3-2. Head Cable Treatment 

Head cable shoiild be arranged correctly by the clampers with appropriate 
margin in length so that the head carriage can move on the guide shafts 
smoothly. 

(1) Claii¥> the head cable with cable clamper B so that the cable has 

appropriate looseness when the head carriage is set to track 00 (rear 
end of the moving area) . The appropriate length of the head cable from 
the head carriage output to the first cable clamper is approximately 
90mm. 




Note: The figure uses the double sided FDD. The same cable arrangement 
is applied to the single sided FDD. 

(Fig. 405) Head cable arrangement 



- 4020 - 



(2) Form the cable not to have excessive looseness in the area from the 
head connector to the cable clamper B. 



- 4021 - 



2-4. Initial Setting of SKA 

Following initial setting is required for operating the SKA. 
2-4-1. Cable connection and setting of power supply voltage 

(1) Set the output voltage of DC power supply to +12V and +5V, approx. 

(2) Turn the DC power off and connect the power cable to the PSA (SKA PWR) 
connector of the SKA. 

(3) Set the FD PWR switch of the SKA to the OFF position. 

(4) Connect the FD PWR OUTPUT of the SKA and the FDD with the SKA/FDD power 
cable . 

(5) Connect the SKA/FDD interface cable. Pay attention to the identification 
mark of the connector (V) so that it locates at the pin 1 and 2 side. 



IX: power supplies 
(+12V, +5V) 



SKA/FDD power cable 




FDD 



(Fig. 406) Connection of SKA cable 



- 4022 - 



(6) Connect the check cable #1 (Flat cable, brown 7P connector at the FDD 

side and white 5P connector at the SKA side) between the terminals 1 'X' 5 
of the SKA and TPl TP6, G of the FDD. For the SKA side, be sure to 
match the pin numbers of the connector housing and the terminal numbers 
of the connector. For the FDD side, cable connection side pins should 
be connected to the TPl 5 side . 



(7) Connect the check cable #2 (shield cable is used partially, 5P connectors 
at both ends) between the terminals 6 9, G of the SKA and TP7 TPlO, 
G of the FDD. Be sure to match the pin numbers of the connector housing 
and the terminal numbers of the SKA as in Fig . 407 . 
The shield cable side is TP7, 8, and terminals 6, 7 of the SKA. 




Cable connection side (TPl'V'5) 

7P 5P 
\ Check cable #1 y 

\ 



FDD TPs 



SKA terminals I'^S 



FDD TPs 



Shield cable side 




j- Shield cable side 
SKA terminals 6'^9,G 



Connector housing No. 



(Fig. 407) Connection of check cable 



(8) Turn the DC power on. Set the FD PWR switch of the SKA to the PSA side. 



(9) Key in "CB". (+5V VOLTAGE) 



(10) Adjust the DC power voltage so that the DATA indicator of the SKA 
I I ^ I 1 (V) indicates the value within the range of 5.6o±0.1V. 



- 4023 - 



(11) Key in "F". (STOP) 



(12) Key in "CC". (+12V VOLTAGE) 

(13) Adjust the DC power voltage so that the DATA indicator of the SKA 

I I J I I (V) indicates the value within the range of 12.00±0.24V. 

(14) Key in "F". (STOP) 

Note: The above items (1), (2), (9) % (14) may be omitted for replacement 
of the FDD or a temporary FDD power off. Remain DC power on and 
control the FDD power by the SKA PWR switch. 



- 4024 - 



4-2-4-2 . Setting of the maximimi track niomber 

Before the check and the adjustment of the FDD, set the maximum track 
number according to the following instructions. 

The setting will be maintained until the main DC power (for SKA) is 
turned off or until the RESET switch of the SKA is depressed. Since 
The FD PWE switch is independent of this setting, it is convenient to 
maintain the main DC power on for the successive operations. 
The initial setting of the following is not required if the maximum 
track number is the same as the initial value (79) of the SKA. 

(1) Key in "CF". (SET TMAX) 

(2) The maximum track number set at that time is indicated with the latter 
two digits of the DATA indicator 1 I I i 1 (track) . 

Note: If there is no chainge in the maximum track number in item (2) , 
depress "F" key. 

(3) Key in a new maximum track number (two digits) in decimal notation. 

e.g. 48tpi: CF 39 (for 40 cylinders) 
96tpi: CF 79 (for 80 cylinders) 
96tpi (High density) : CF 76 (for 77 cylinders) 



- 4025 - 



4-2-4-3. Setting of step rate and settling time 

Before check and adjustment of the FDD, set the step rate and the 

settling time according to the following instructions - 

The setting will be maintained until the main DC power (for SKA) is 

turned off or until the RESET switch of the SKA is depressed. 

If the step rate and the settling time are the same as the initial 

values of the SKA (step rate: 6msec, settling time: 15msec), the 

initial setting of the following is not required. This case is applied 

to 48tpi FDDs. 

(1) Key in "DB". (SET STEP RATE) 

(2) Step rate set at that time is indicated by 0.1msec scale on the DATA 
indicator . t I I J I (ms) . 

e.g. DATA indicator 1 I Ifi^l^l indicates 6.0msec. 

(3) Key in a new step rate down to one decimal place (unit: msec). 

Note: If there is no change in step rate in item (2), omit item (3) and 
forward to item (4) . 

(4) Key in "F" . (STOP ~ Setting of the step rate completes.) 

(5) Settling time at that time is indicated by 0.1msec scale on the DATA 
indicator I I I J ) (ms) 

e.g. DATA indicator I |/|5|g| indicates 15.0msec. 

(6) Key in new settling time down to one decimal place (unit: msec). 

Note: If there is no change in settling time in item (5), omit item (6) 
and depress "F" key to complete the operation. 



- 4026 - 



(7) Depress "F" key. (STOP — Setting of the settling time completes.) 



e.g. 48tpi FDD: DB 60 F 150 F 

(Step rate: 6msec, settling time: 15msec) 
96tpi FDD: DB 30 F 150 F 

(Step rate: 3msec, settling time: 15msec) 



- 4027 - 



4-2-4-4. Level disk calibration 

Setting of the following calibration value is required for accurate 

measurement before the check of the read level or the resolution. 

Use a level disk with a calibration value (100% center) written on the 

label. The setting will be maintained until the main DC power (for SKA) 

is turned off or until the RESET switch of the SKA is depressed. 

If the calibration value is the same as the initial value (100%) of the 

SKA, the initial setting of the following is not required. 

(1) Innermost track read level 

(a) Key in "DO". (CALIBRATION READ LEVEL) 

(b) Calibration value set at that time is indicated in the latter three 
digits of the DATA indicator I I I I I (%) . 

(c) Key in a new calibration value written on the level disk label 
(three digits. Max.) 

(d) Key in "F" . (STOP) 

Note: If there is no calibration change in item (b) , omit item (c) cind 
depress "F" key. 

(2) Innermost track resolution 

(a) Key in "Dl". (CALIBRATION RESOLUTION) 

(b) Calibration value set at that time is indicated in the latter 
three digits of the DATA indicator I I i I I (%) . 

(c) Key in a new calibration value written on the level disk label 
(three digits. Max.) 



- 4028 - 



(d) Key in "F" . (STOP) 

Note: If there is no calibration change in item (b) , omit item (c) and 
depress "F" key. 

e.g. READ LEVEL 103%, RESOLUTION 96%: DO 103 F, Dl 96 F 



- 4029 - 



4-2-4-5. Alignment disk calibration 

Setting of the following calibration value is required for accurate 

measurement before the check and adjustment of the track alignment. 

Use a correctly calibrated (0% center) alignment disk with a calibration 

value written on the label. The setting will be maintained until 

the main DC power (for SKA) is turned off or until the RESET switch of 

the SKA is depressed. 

If the calibration value is the same as the initial value (0%) of the 
SKA, the initial setting of the following is not required. 

(1) SIDE alignment 

(a) Key in "EO". (CALIBRATION SIDE ALIGNMENT) 

(b) The calibration value set at the time. is indicated in the latter two 
digits of the DATA indicator I I I I I (%) , and the polarity is indicated 
in the initial digit. If a "0" is indicated, the polarity is positive. 
Polarity indication: plus /- , minus - 

(c) Key in a polarity and a new calibration value (two digits. Max.) 
written on the alignment disk label. 

Designation of polarity: Depress "B" key only for minus designation. 

(No designation is required for plus) . 

(d) Key in "F". (STOP) 

(2) Side 1 alignment (Double sided only) 

(a) Key in "El". (CALIBRATION SIDE 1 ALIGNMENT) 

(b) The same as in item (l)-(b) 'v (d) . 



- 4030 - 



INDEX output signal 



TJ 



Lobe pattern 
(TP9,10) 




Notes: 1- The lobe pattern raticJ is calibrated in the SKA according to 
the following expression. 

Lobe pattern ratio = — ^-^ ^ ^ ^ ^ xlOO-Calibration value (%) 

^ Larger one of A & B 

after calibration 

2- If the calculated value with the above expression is positive, 
the polarity is plus, while the polarity is minus when the 
value is negative. 

(Fig. 408) Calibration of alignment lobe pattern 
(3) Index burst timing 

(a) Key in "E5". (CALIBRATION INDEX TIMING) 

(b) The calibration value set at that time is indicated in the latter 
three digits of the DATA indicator Mill (ys) , and the polarity is 
indicated in the initial digit. (Refer to item (l)-(b)): 

If a "0" is indicated, the polarity is positive. 

(c) Key in a polarity and a new calibration value (three digits. Max.) 
written on the alignment disk label. Refer to item {l)-(c) for the 
polarity designation. 

(d) Key in "F". (STOP) 

Note: If there is no change in the calibration value in item (b) , omit 



- 4031 - 



item (c) and depress "F" key. 

e.g. Double sided FDD, SIDE ALIGNMENT +3%, SIDE 1 ALIGNMENT -5%, 
INDEX TIMING -25ys: 
EO 3 F, El B 5 F, E5 B 25 F 



INDEX output signal 



H Index burst timing 

Notes: 1. The index timing is calibrated in the SKA according to the 



following expression. 

Calibrated timing = t - calibration value (Ms) 

2. If the calculated value with the above expression is 

positive, the polarity is plus, while the polarity is minus 
when the value is negative. 

(Fig. 409) Calibration of index burst timing 



Index burst (TP7,8) 




t 



- 4032 - 



4-2-4-6. Humidity setting 

For the check and adjustment of the track alignment using an alignment 
disk, set the environmental relative humidity to the SKA in order to 
improve the precision of measurement. 

This setting is important when the relative humidity is considerably 
different from 50% at the 96tpi FDD. 

The initial setting of the following is not required if the relative 
humidity is the same -as the initial value (50%) of the SKA. 

(1) Key in "E2". (CALIBRATION RH ALIGNMENT) 

(2) The relative humidity set at that time is indicated in the latter 
two digits of the DATA indicator I I I I I (%). 

(3) Input the relative humidity percentage in the measurement environment 
(two digits, Max.). 

e.g. 96tpi, RH 58%: E2 58 

4-2-4-7. Setting of SKA gain 

Following setting is required for the check and adjustment of the 96tpi 
FDD. 

(1) Key in "DD" and confirm that the H GAIN indicator is on. 

Note: Above setting shall not be done for 48tpi. If the H GAIN indicator 
is on, turn it off by keying in "DD". 



- 4033 - 



4-2-5. Others 

(1) Total error test 

In the check and adjustment in item 4-4, read/write error test is not 
included. After the adjustment or the replacement of the maintenance 
parts, it is recommended to perform a data error test by connecting the 
FDD to the user's system or the TEAC simulator KB. The window margin 
test is the most recommended item. 

(2) Setting of FDD straps and SKA special keys 

It is required to confirm before the operation that the straps (short 
bars) on the PCBA MFD control are at the appropriate position for the 
system to be sued in the check and adjustment. 

For the purpose of simplyfying the explanation, it is recommended to 
set the following straps on when you use the SKA. However, if you 
can set the straps correctly referring to Specification, Instruction 
Manual, Schematic diagrams, and SKA Instruction Manual, you need not to 
follow this recommendation. 

(a) FDD with head load solenoid: 

Set HS, DS 0, and SM straps on. No restriction for the straps lU, PM, 
and RE. Other straps should be set to off -state. 

(b) CSS model (without head load solenoid) FDD: 

Set DS strap on. No restriction for the straps lU, PM, and RE. 
Other straps should be set to off -state. 

Note: The signal level of the interface connector pin 4 (IN USE/HEAD 
LOAD) can be alternately changed between TRUE and FALSE by 
depressing "A" (IN USE) key of the SKA. When it becomes TRUE, "A" 
indicator of the SKA turns on. Refer to the Specification as to 
the function of the signal and straps . 



- 4034 - 



If the strap position of the FDD is changed from the initial setting 
at the system installation, be sure to change it back, to the initial 
position after maintenance. 

(3) Terminator 

When you check each FDD with a maintenance system such as the SKA, 
it is necessary to put the terminator network into the IG -socket J3 on 
the PCBA MFD control. The terminator shall be returned to the initial 
condition after completion of the maintenance. 

(4) Connection of the probe ground 

Connect the probe ground of the equipment as follows: 

(a) For the observation at the test points (TP) 7 % 10: 

Connect the probe ground to the G test point (OV) on the PCEA MFD 
control - 

(b) For the observation at the other test point: 

Connect the probe ground to the G test point (OV) on the PCBA MFD 
control. Or GND (OV) terminal of the system power supply unit, or 
the SKA GND terminal may be used. 

(c) For the observation of the SKA test point: 
Connect the probe ground to the SKA GND terminal. 

Note: When you use the SKA, almost all checks including the read amp. 

output at TP7 'x. TPIO of the FDD will be done automatically through 
the check cables #1 and #2 and interface cable. Also these signals 
can be observed by an oscilloscope using the test points on the SKA. 

(5) Maintenance environment 



- 4035 - 



Maintenance of the FDD should be done on a clean bench at room 
temperature and humidity. It is recommended to execute the check and 
adjustment of the track alignment after leaving the FDD for at least 
2 hours at room tempera t\ire and humidity. The magnetic head, disk, 
steel belt, etc, might suffer from dust and dirt if the maintenance is 
not undertaken in a clean environment. 

(6) Orientation of the FDD 

Position the FDD as shown in Fig. 410 unless otherwise specified. 
Horizontal and vertical orientations with lever side up should be used. 



Lever 



Horizontal setting 



Vertical setting 



(Fig. 410) General orientation of the FDD during maintenance 

(7) Head load of the CSS model 

For the CSS model (without head load solenoid) , the FDD is always in 
head load condition as far as a disk is inserted and the front lever 
is closed. 

(8) Work disk 

When you use the SKA, use a soft sectored disk. 



(9) Disks for high density FDD {FD-55G) 



- 4036 - 



For the check and adjustment of the high density FDD, it is required to 
use a high density disk (HD disk) as a work disk or as the level disk. 
The high density disks look more transparent when viewed through than 
the ordinary disk. 



- 4037 - 



3. PREVENTIVE MAINTENANCE 



3-1. Cleaning of Magnetic Head by Cleaning Disk 

When you use the FDD in dusty environment, it is recommended to clean 
the magnetic head surface periodically (e.g. once a month) with a 
commercially available cleaning disk. Especially for a double sided 
FDD, it is difficult to clean the head surface, be sure to use the 
cleaning disk. 

For typical usage under typical environmental condition, the clenaing 
is recommended when data errors often occur. 

(A) Equipment 

(1) Cleaning disk 

(2) SKA or user's system 

(B) Cleaning procedure 
(1) General method 

(a) Start the spindle motor and install an appropriate cleaning disk. 

Notes: 1. Do not use a damaged cleaning disk on the surface. 

2. For a single sided FDD, be sure to install a single sided 
cleaning disk. The cleaning surface of the disk should be in 
contact with the head surface. 

When the FDD is placed horizontally, the magnetic head is 
located down and it faces the back side of the disk. 
If a double sided cleaning disk is installed in a single sided 
FDD, it may dcimage the head pad. 

3. For a double sided FDD, a double sided cleaning disk should be 
used. Side (lower side) and side 1 (upper side) heads are 
cleaned simultaneously. 



- 4038 - 



(b) Execute head loading and clean the head at a suitable track position 
for 10 % 30 seconds, approx. In order to avoid the concentration on 
a specific track, it is a good way to make the head move between 
track 00 and the innermost track during cleaning. 

Note: The most appropriate cleaning time is different for each type of 
cleaning disk used. 

Excessively long cleaning time is not effective but has possibility 
to accelerate the head wear. 

(c) Remove the cleaning disk. 
(2) SKA method 

(a) Connect the SKA referring to item 4-2-4 and set the FD PWR switch to 
the PSA side. 

(b) Start the spindle motor by key "5". (MON indicator turns on) . 

(c) Execute drive select by key "0". (DSO indicator turns on). 

(d) Key in "CO" and confirm that the TRACK indication of the SKA becomes 
"00". (RECALIBRATE) 

(e) Install an appropriate cleaning disk. See item (l)-{a), "Notes". 

(f) Key in "C6" . (SEEK TEST) 

(g) After 10 % 30 seconds, depress "F" key. 

(h) Eject the cleaning disk. 



- 4039 - 



4-3-2. Direct Cleaning (Single sided FDD only) 

This cleaning method is applied only to a single sided FDD. 

If this method is applied to a double sided FDD, gimballed mechanism 

might be damaged . 

If visible dirt is on the head surface when the head pad arm is lifted 
up manually during maintenance, perfoinn direct cleaning as follows: 

(A) Equipment 

(1) Absolute alcohol (Ethanol) 

(2) Cotton swab or gauze 

(B) Cleaning procedure 

(1) Lightly dampen a cotton swab or a gauze with alcohol. 

(2) Lift up the pad arm (see Fig, 411) and clean the head surface carefully 
with the cotton swab or the gauze. 

Note: Do not touch the pad surface. 

(3) Wipe the head surface with clean dry cloth after the evaporation of the 
alcohol . 

(4) After confirming that the dirt is cleaned off and no fluff is left on 
the head surface, let the pad arm down carefully. 



- 4040 - 




(Fig. 411) Direct cleaning of the magnetic head (Single sided only) 



-4041 - 



4. CHECK AND ADJUSTMENT 



4-1. Adjustment of Set Arm Position 

(A) Equipment 

(1) Cross point screwdriver, M3 

(2) Locking paint 

(B) Adjustment procedure 

(1) Loosen two fixing screws of the set arm (see Fig. 412) so that the set 
arm can be moved manually without getting out of place. 

(2) Close the set arm by turning the front lever. 

(3) In this condition (item (2)), adjust the set arm so that. the visual 
distance of the gap between the collet shaft and the set arm hole 
becomes even. 

(4) Tighten the installing screws of the set arm with the specified torque, 
apply a drop of locking paint on the screw head. 

(5) Open and close the set arm by turning the front lever and confirm that 
it does so smoothly. 



- 4042 - 




(Fig. 412) Adjustment of set arm position 



- 4043 - 



4-4-2. Adjustment of Clamp Arm Position 

(A) Equipment 

(1) Cross point screwdriver, M3 

(2) SKA or user's system 

(3) Work disk 

(B) Adjustment procedure 

(1) Loosen four holder fixing screws (see Fig. 4 13) so that the holder can 
be moved manually without getting out of place. 

(2) Close the set arm by turning the front lever. 

(3) Push down the holder against the frame so that narrow gap is spaced 
between the E-ring on the collet shaft and the set arm plate, then 
tighten the four screws at both sides. 

Narrow gap should be confirmed by a very easy manual turning of the 
E-ring , 

(4) Install a work disk. 

(5) Start the spindle motor and confirm that the disk rotates smoothly. 
When the SKA is used, connect the SKA referring to item 4-2-4 and set 
the FD PWR switch to the PSA side. Then start the spindle motor by 
key "5". (MON indicator turns on). 

(6) Place the FDD vertically (refer to Fig. 410) . 

(7) Nip the disk edge firmly with fingers which appears a little from the 
front bezel, and confirm that the rotor of the spindle motor stops. 

(8) If the spindle motor does not stop completely, push down the holder 



- 4044 - 



further against the frame at item (3) . Then execute the procedure 
from item (4) through (7) again. 

(9) Eject the work disk. 
(10) Adjust the front lever position according to item 4-4-3. 




(two for each side) 



(Fig, 413) Adjustment of clamp arm position 



- 4045 - 



4-4-3. Adjustment of Front Lever Position 

(A) Equipment 

(1) Hexagon wrench key, 1.5mm 

(2) MAX media jig 

(B) Adjustment procedure 

(X) Turn the front lever to open position and loosen a lever fixing set 
screw (see Fig. 414) . 

(2) Turn the front lever to close position and loosen another fixing screw. 
Then pull out the lever for 0.5mm, approx. 

(3) Tighten the screw in item (2). 

(4) Open the front lever and insert the MAX media jig from the notch side. 
(See Fig. 414) . 

(5) Turn the front lever to close position and loosen the lever fixing 
screw again. Then push the lever against the MAX media jig. 

(6) Position the handle of the front lever forms right angle against 
the longitudinal side of the front bezel. And tighten the set screw 
with the specified torque. (see Fig. 415) . 

(7) Turn the front lever to open position and tighten another set screw 
in the same manner. 

(8) caose the front lever and confirm that the blade of the lever does not 
nip the MAX media jig. 

(9) Open the front lever and remove the jig. 



- 4046 - 



Note: Refer to item 4-2-1 as to handling of the set screws- 




-lever fixing screws 



Front lever 



MAX media jig 
(Fig- 414) Adjustment of front lever 



Front bezel 



Sectional view of 
front bezel 

Front lever 



CD 




A i=?i 


1^=^ 1 


















Blade 



Form right auigle 



(Fig. 415) Front lever position 
- 4047 - 



4-4. Adjustment of Arm Lifter 

This item applies only for the FDD with the head load solenoid. 
The adjusting method is different between the single sided FDD and 
the double sided FDD. 

4-4-1. Double sided FDD (Adjustment of arm lifter) 
(A) Equipment 

(1) Hexagon wrench key, 1.5mm 

(2) Work disk 

(3) SKA or user's system 

(4) Oscilloscope 

(5) Locking paint 

(Bl Adjustment procedure 
(1) General method 

(a) Start the spindle motor and insert a work disk. 

(b) Set the head to track 00. 

(c) Execute head loading. 

(d) Turn the adjusting screw (set screw) of the arm lifter so that the 
gap between the upper arm and the arm lifter becomes 0.2mm,Min. 
(See Figs. 416 and 417). 

(e) Unload the head. 

(f) Confirm that the upper arm is lifted slightly by the arm lifter. 



- 4048 - 




(Fig. 416) Adjustment of arm lifter 




Note: Viewed from front bezel side 
(Fig. 417) Gap of arm lifter 



- 4049 - 



(g) Use two channels of oscilloscope. Connect the 1st channel to the 
head load command signal and the 2nd channel to TP9 or TPIO on the 
PCBA MFD control. Triggering is done by the head load command. 

Oscilloscope range 

The 1st channel: DC mode, 2V,. 10msec 
The 2nd channel: AC mode, 0.5V, 10msec 

Note: For example, when you execute the head loading using a DRIVE • 

SELECT signal, it is required to set DS (one of through 3), HS, 
and SM straps on. 

For the purpose of check and adjustment in this item, it is not 
proper to execute the head loading by the MOTOR ON signal with HM 
and SM straps on. Use either of the DRIVE SELECT signal or the 
IN USE/HEAD LOAD signal. (See the Specification item 1-12-3). 

(h) Select the side 1 head. 

(i) Execute head loading 

(j) Execute 2F write operation for one rotation of the disk (250KHz of 
WRITE DATA frequency for FD-55A -x. F, SOOKHz for FD-55G) . 

(k) Unload the head. 

(L) Repeat the head loading and unloading alternately (tapping operation) 
and observe the waveform of TP9 or TPIO by the oscilloscope. 
(See Fig. 418) . 

(m) Set the oscilloscope trigger to the positive mode and observe the read 
waveform at TP9 or TPIO after the input of an unload command. Confirm 
that there is no big spike noise (excludes a small one) or there is 
not a continuous unload level (excludes the noisp level) as shown 
by dotted line in Fig. 418. 



- 4050 - 



Head load command 



TP9 or TPlO 



TRUE 




Head load command 



Head unload command — 
TP9 or TPlO 



Head load time {35ms) 



FALSE 




Spike noise 



Residual read level 
(Unload level) 



Head unload command 



(Fig. 418) Read waveforms at head loading/ unloading 



In such event that either of the spike noise or continuous unload 
level is observed in the waveform, fine adjust the set screw of the 
arm lifter. 



Note: This item should be executed when the side 1 head is selected. 
If the side 1 head is lifted too high during unload operation, 
spike noise will be observed, while unload level will be observed 
when it is too low. 

(n) Set the oscilloscope trigger to the negative (-) mode and observe 
the waveform at TP9 or TPlO after the input of a head load command. 
Confirm that the read waveform more than 35msec after the head load 
command is almost static. 



- 4051 - 



As a detail, bottom "A" of the read level more than 35msec after 
the input of the head load command should be more than 0.7 against 
the average read level "B". (A/B >^ 0.7 in Fig. 418) 

(o) Make the head move to the innermost track. 

(p) Repeat the procedure from item (i) to in) and adjust so that the 
items (m) and (n) are satisfied at track 00 and at the innermost 
track . 

(q) The items (m) and (n) are applied to the side head. However, as 
to the unload level in item (m) will be excluded unless it is the 
same read level as the head load condition. 
Confirm in the same manner by selecting the side head. 

(r) Again set the head to track 00. 

(s) After opening the front lever, draw out the disk slowly. In the 

process of drawing out, the side and side 1 heads shall not catch 
the head, window edge of the disk jacket (opening area of the jacket 
to make the head be in contact with the disk surface) . The jacket 
can be drawn out smoothly with appropriate space margin. 

(t) Insert the disk slowly and confirm that the disk jacket does not 

touch the side nor side 1 head and goes into the FDD smoothly with 
appropriate space margin. 

(u) If the items (p) , (g) , (s) , or (t) is out of the specification, 
following causes are assumend. 

i) Inferior disk: 

Disk and/or jacket is deformed or the disk may have drop-out«. 
In such event, replace the work disk with a new one. 



- 4052 - 



ii) Inferior head carriage Ass'y: 

Replace the head carriage Ass'y according to item 4-5-1. 
iii) Inferior head load solenoid: 

Replace the head load solenoid Ass'y according to item 4-5-5. 
iv) Inferior PGBA MFD control: 

Replace the PCBA MFD control according to item 4-5-7. (No relation 
to items (s) and (t)). 



Note: Refer to item 4-2-1 as to handling of the set screw. 

If the strap setting is changed, back it to the initial setting 
after the adjustment. 



- 4053 - 



(2) SKA method 

(a) Connect the SKA according to item 4-2-4 and set the FD PWR switch to 
the PSA side. 

(b) Start the spindle motor by key "5". (MON indicator turns on). 

(c) Install a work disk. 

(d) Execute drive select by key "0". (DSO indicator turns on). 

(e) Key in "CO" and confirm that the TRACK indication becomes "00". 
(RECALIBRATE) 

(f) Turn the adjusting screw (set screw) of the arm lifter so that the 
gap between the arm lifting area of the upper arm and the arm lifter 
becomes 0.2mm, Min. (See Figs. 416 and 417) . 

(g) Release the drive select by key "0". (DSO indicator turns off). 

(h) Confirm that the upper arm is lifted slightly by the arm lifter. 

(i) Use two channels of socilloscope . Connect the 1st channel to the 
DOUT terminal and the 2nd channel to the DIF terminal of the SKA. 
Apply negative trigger by the DOUT terminal. 

Oscilloscope range 

The 1st channel: DC mode, 2V, 10msec 
The 2nd channel: AC mode, 0.5V, 10msec 

Note: For the check and adjustment in this item, it is required to set 
on the straps DS 0, HS, and SM of the FDD. (See item 4-2-5- (2)). 

(j) Key in "BC F". (DRIVE SELECT observation) 



- 4054 - 



(k) Select side 1 head by key "4". (SIDE 1 indicator turns on). 
(L) Execute drive select by key "0". (DSO indicator turns on), 
(m) Key in "C9". (HEAD LOAD TIME) 

(n) Observe the waveform of the DIF terminal at head unloading using the 
oscilloscope . 



SKA DOUT 



SKA DIF 




Spike noise 



Residual read level 
(Unload level) 



Head unload command 



(Fig-419) Read waveform at head unloading 

(o) Confirm that there is no big spike noise (excludes a small one) or 
there is not a continuous unload level (excludes the noise level) as 
shown by dotted line in Fig. 419. 

In such event that either of the spike noise or continuous unload level 
is observed in the waveform, fine adjust the set screw of the arm 
lifter. 

Note: This item should be executed when the side 1 head is selected 
(SIDE 1 indicator turns on) . 

If the side 1 head is lifted too high during unload operation, 
spike noise will be observed, while unload level will be observed 
when it is too low. 



(p) Confirm that the DATA indicator Mill (%) of the SKA indicates a 
value within the following range. 
Head load settling level after 35msec: 70%, Mm. 

- 4055 - 



(q) Key in "F". (STOP) 



(r) If the DSO indicator of the SKA is off, execute drive select by key 
"0". (DSO indicator turns on). 

(s) Key in "CI". (SEEK TMAX) . 

(t) Repeat the procedure from items (in) to (p) and adjust so that the 
items (o) and (p) are satisfied at track 00 and at the innermost 
track . 

(u) Key in "F". (STOP) 

(v) The items (o) and (p) are applied to the side head. However, as 
to the unload level in item (o) will be excluded unless.it is the 
same read level as the head load condition. 

Depress key "4" to turn off the SIDE 1 indicator of the SKA and 
confirm in the same procedure of items (L) through (u) for the side 
head. 

(w) Key in "CO" and confirm that the TRACK indication becomes "00". 
(RECALIBRATE) 

(x) After opening the front lever, draw out the disk slowly. In the 

process of drawing out, the side and side 1 heads shall not catch 
the head window edge of the disk jacket (opening area. of the jacket 
to make the head be in contact with the disk surface) . The jacket 
can be drawn out smoothly with appropriate space margin. 

(y) Insert the disk slowly and confirm that the disk jacket does not 

touch the side nor the side 1 head and goes into the FDD smoothly 
with appropriate space margin. 

(z) If the items (t) , (v) , (x) , or (y) is out of the specification, refer 
to item (u) of "General method". 

- 4056 - 



Note: Refer to item 4-2-1 as to handling of the set screw. 



- 4057 - 



4-4-4-2. Single sided FDD (Adjustment of arm lifter) 

(A) Equipment 

(1) Hexagon wrench key, 1.5mm 

(2) Work disk 

(3) SKA or user's system 

(4) Locking paint 

(B) Adjustment procedure 
(1) General method 

(a) Start the spindle motor and insert a work disk. 

(b) Set the head to track 00, 

(c) Execute head loading. 

(d) Turn the adjusting screw (set screw) of the arm lifter so that the 
gap between the pad arm and the arm lifter becomes 0.2mm, Min. (See 
Figs. 416 and 417) . 

(e) Unload the head. 

(f) Confirm that the pad arm is lifted slightly by- the arm lifter. 

(g) Make the head move to the innermost track. 

(h) Load the head and repeat the procedure from item (d) to (f ) . 

(i) Again set the head to track 00. 



- 4058 - 



(j) Repeat the procedure from item (c) to (f ) . 
Note: Refer to item 4-2-1 as to handling of the set screw. 



- 4059 - 



(2) SKA method 

(a) Coimect the SKA according to item 4-2-4 and set the FD PWR switch 
to the PSA side. 

(b) Start the spindle m.otor by key "5". (MON indicator turns on). 

(c) Install a work disk. 

(d) Execute drive select by key "0". (DSO indicator turns on). 

(e) Key in "CO" and confirm that the TRACK indicator becomes "00". 
(RECALIBRATE) . 

(f) Turn the adjusting screw {set screw) of the arm lifter so that the 
gap between the pad arm and the arm lifter becomes 0.2mm, Min. 
(See Pigs. 416 and 417) . 

(g) Release the drive select by key "0". (DSO indicator turns off). 

(h) Confirm that the pad arm is lifted slightly by the arm lifter. 

(i) Execute drive select by key "0". (DSO indicator turns off), 

♦ 

(j) Key in "CI" (SEEK TMAX) . 

(k) Repeat the procedure from item (f) to (1) . 
(L) Key in "CO" (RECALIBRATE) , 

(m) Repeat the procedure from item (f) to (i) . 

Note: Refer to item 4-2-1 as to handling of set screw. 

- 4060 - 



4-4-5. Check of CSS Ass'y 

This item appiies only to the double sided CSS model (without head load 
solenoid) . 

Equipment 

(1) Work disk 

(2) SKA or user's system 

(B) Check procedure 
(1) General method 

(a) Open and close the front lever with no insertion of a disk. 

(b) Confirm that the side 1 head is lifted even if the front lever is 
close and it has enough gap against the side head, (See Fig. 420) . 



(c) After opening the front lever, insert a work disk slowly. 

Confirm that the disk jacket does not touch the side nor side 1 head 
and goes into the FDD smoothly with appropriate space margin. 




Side 1 head 



Side head 



(Fig. 420) Gap between side and side 1 heads 



- 4061 - 



(d) Draw out the disk slowly. Confirm that the side and side 1 heads 
do not catch the head window edge of the disk jacket (opening area 
of the jacket to make the head be in contact with the disk surface) 
and that the jacket can be drawn out smoothly with appropriate 
space margin. 

(e) Confirm that the cam (natural color) of the CSS Ass'y attached to the 
left side Of the head carriage moves as in Fig. 421 by opening/closing 
of the front lever and insertion/ejection of the disk. 




i) Disk is not fully inserted. ii) Disk is fully inserted and 

front lever is close. 

(Fig. 421) Rotation of CSS Ass'y cam 

(f) Start the spindle motor and insert a work disk. 

(g) Set the head to track 00. 

(h) In the close condition of the front lever, confirm that the gap 
between the upper arm (double sided) or the pad arm (single sided) 
and the arm lifter is 0.2mm, Min. See Fig. 418. 

(i) Make the head move to the innermost track, 
(j) Confirm as in item (h) . 



- 4062 - 



(2) SKA method 

(a) Open and close the front lever with no insertion of a disk. 

(b) Confirm that the side 1 head is lifted even if the front lever is 
close and it has enough gap against the side head. (See Fig. 420) . 

(c) After opening the front lever, insert a work disk slowly. 
Confirm that the disk jacket does not touch the side nor side 1 
head and goes into the FDD smoothly with appropriate space margin. 

(d) Draw out the disk sJowly. Confirm that the side and side 1 heads 
shall not catch the head window edge of the disk jacket (opening 
area of the jacket to make the head be in contact with the disk 
surface) and that the jacket can be drawn out smoothly with appropriate 
space margin. 

(e) Confirm that the cam (natural color) of the CSS Ass'y attached to the 
left side of the head carriage moves as in Fig. 421 by opening/closing 
of the front lever and insertion/ejection of the disk. 

(f) Connect the SKA according to item 4-2-4 and set FD PWR switch to PSA 
side . 

(g) Start the spindle motor by key "5". (MON indicator turns on). 

(h) Execute drive select by key "0". (DSO indicator turns on). 

(i) Key in "CO" and confirm that the TRACK indication becomes "00". 
(RECALIBRATE) 

(j) In the close condition of the front lever, confirm that the gap- 
between the upper arm (double sided) or the pad arm (single sided) 
and the arm lifter is 0.2mm, Min. See Fig. 418. 



- 4063 - 



(k) Key in "CI". (SET TMAX) . 
(L) Confirm as in item ( j) . 



- 4064 - 



4-4-6. Check of File Protect Sensor 
(A) Equipment 



(1) MAX media jig 

(2) Digiral voltmeter (or oscilloscope) 

( 3 ) SKA or user ' s system 



(B) Check procedure 
(1) General method 



(a) Place the FDD on the work bench with the LED indicator up and the 
front lever down. (See Fig. 422). 

(b) Connect a digital voltmeter or an oscilloscope (DC range, IV/div) 
to TP6 (File protect sensor) on the PCBA MFD control.. 

(c) Install the MAX media jig from the notch side and set it so that the 
notch A area is located on the light pass from the file protect 
sensor LED. (See Fig. 422). 

(d) Adjust the orientation of the FDD so that it is not exposed with 
strong light outside. 



(e) Confirm that the voltage measured at TP6 when power is supplied to 
the FDD is within the following range , 

Notch A position TP6 voltage: 3.0V, Min, 

(f) Pull out the jig a little so that the notch B area is located on the 
light pass. 



(g) Confirm that the voltage measured at TP6 when power is supplied to 
the FDD is within the following range . 



- 4C65 - 



Notch B position TP6 voltage: 0.5V, Max. 




- 4066 - 



(2) SKA method 

(a) Connect the SKA according to item 4-2-4 and set the FD PWR switch to 
the PSA side. 

(b) Execute the general method described in item (l)-{a) through (e) . 
WRROT indicator of the SKA turns on when drive selection is executed 
by key "0". (DSO indicator turns on). 

(c) Execute the general method described in item (l)-(f) and -(g). 
WRROT indicator of the SKA turns off. 



- 4067 - 



4-4-7. Check and Adjustment of Disk Rotation Speed 



This item is only applied to the FDD which has a DD motor Ass'y with 

the variable resistor Rl for adjusting the rotational speed of the 

disk on the PCBA DD motor servo. Refer to Fig. 311 as to the mounting 
position of the valiable resistor Rl. 

For the DD motor Ass'y without the variable resistor, the rotation 

speed is fixed by the ceramic oscillator in the servo circuit and no 
adjustment is required. 

(A) Equipment 

(1) Common screwdriver, small size 

(2) SKA or user's system 

(3) Frequency counter (not required when the SKA is used) 

(4) Work disk (soft sectored) 

(B) Check and adjustment procedure 
(1) General method 

(a) Connect the frequency counter to TP4 (Index) of the PCBA MFD control 
or to the INDEX interface signal line. 

(b) Start the spindle motor and install a work disk. 

(c) Set the head to track 00. 

(d) Execute the head loading. 

(e) Confirm that the pulse interval at TP4 is within the following range. 
FD-55A F: 200±3msec 

FD-55G : 166 . 7±2 . Srasec 



- 4068 - 



If the value in item (e) is out of the specified range, adjust the 
variable resistor Rl on the PCBA DD motor servo to obtain the median 
value in the specified range in item (e) . 



- 4069 - 



(2) SKA method 



(a) Connect the SKA referring to item 4-2-4 and set the FD PWR switch 
to PSA side. 

(b) Start the spindle motor by key "5". (MON indicator turns on). 

(c) Insert a soft sectored work disk. 

(d) Execute drive select by key "0". (DS indicator turns on). 

(e) Key in "CO" and confirm that TRACK indication becomes "00". 
(RECALIBRATE) 

(f) Key in "C3". (INDEX PERIOD) 

(g) Confirm that the DATA indicator I I N I (ms) indicates a value within 
the following range. 

FD-55A 'V^ F: 200 . 0±3 . 0msec 
FD-55G : 166. 7±2. 5msec 

(h) If the value in item (g) is out of the specified range, adjust the 
variable resistor Rl on the PCBA DD motor servo to obtain the median 
value in the specified range in item (g) . 



- 4070 - 



4-4-8. Check and Adjustment of Erase Gate Delay 

(A) Equipment 

(1) Common screwdriver, small size 

(2) Work disk 

(3) SKA or user's system 

(4) Oscilloscope (not required when the SKA is used) 

(B) Check and Adjustment procedure 
(1) General method 

(a) Use two channels of oscilloscope. Connect the trigger channel to 
WRITE GATE interface line and the other channel to TP2 (Erase gate 
delay) on the PCBA MFD control. 

Oscilloscope range: For both channels, DC mode, 5V, lOOusec 

(b) Start the spindle motor and install a work disk. 

(c) Execute head loading. 

(d) Set the oscilloscope to the negative trigger (-) mode. Make the 
WRITE GATE signal TRUE (write command) . 

(e) Confirm that "t" (Erase on delay) in Fig. 423 is within the following 
range . 

t (Erase on delay): 200 320iisec (FD-55A % F) 

175 'V 210ysec (FD-55G) 

(f) Set the oscilloscope to the positive trigger (+) mode.. Make the WRITE 
GATE signal FALSE. 



- 4071 - 



WRITE GATE 



TP2 

(Erase gate) 



-Erase on delay 



(Fig. 423) Erase on delay 



Confirm that "t" (Erase off delay) in Fig. 424 is within the following 
range . 

t (Erase off delay): 860 '\. 950ysec (FD-55A % F) 

500 550usec (FD-55G) 



WRITE GATE 



TP2 (Erase gate) 



Erase off delay 



(Fig. 424) Erase off delay 



- 4072 - 



(2) SKA method 



(a) Connect the SKA according to item 4-2-4 and set the FD PWR switch to 
PSA side- 

(b) Execute drive select by key "0". (DSO indicator turns on). 

(c) Key in "7". (WRITE GATE ON) 

(d) Confirm that the DATA indicator I, I I I J (ys) shows a value within the 
following range. 

Erase on delay: 200 320ysec (FD-55A F) 
175 'v 210ysec (FD-55G) 

(e) Key in "7" again. (WRITE GATE OFF) 

(f) Confirm that the DATA indicator I I I I I (ys) shows a value within th€ 
following range. 

Erase off delay: 860 950ysec (FD-55A F) 
500 550psec (FD-55G) 



- 4073 - 



4-4-9. Check and Adjustment of Head Touch 

Note: The adjustment applies to a single sided FDD only. 

(A) Equipment 

(1) Work disk 

(2) Common screwdriver, small size 

(3) SKA or user's system 

(4) Oscilloscope (not required when the SKA is used) 

(5) DC clip on ammeter (not required when the SKA is used) 

(6) Locking paint 

(B) Adjustment procedure 
(1) General method 

(a) Connect an oscilloscope to TP9 or TPlO (Differentiation amp.) on the 
PCBA MFD control. 

Oscilloscope range 48tpi: AC mode, 0.2V 

96tpi: AC mode, O.lV 

(b) Start the spindle motor and install a work disk. 

(c) Set the head to the innermost track. 

(d) Execute head loading. 

(e) Repeat the cycle of one write rotation and one read rotation. 
Write data should be the fixed pattern of 2F(250KHz of WRITE DATA 
frequency for FD-55A F, SOOKHz for FD-55G) . 

(f) Write down the average read level measured during the read operation 
of item (e) . 



- 4074 



(g) Execute item (e) and (f) with a slight depression (very slight 
depression easy to release: 10 % 20g) by a finger on the top of the 
upper head (doable sided) or of the pad arm (single sided) , and 
measure the average read level as in item (f) . 

(h) Confirm that the read level measured in item (f) is greater than 80% 
of that in item (g) . 

(i) For a double sided FDD, execute items (e) through (h) respectively 
for side and side 1 heads. 

(j) After making the head move to track 00, execute items (e) through (i) , 

(k) Head touch adjustment for a single sided FDD: 

i) At the innermost track, turn the groove on the upper side of the 
head pad by 30" steps, approx. with a common screwdriver (see 
Fig. 425). At each turning of the groove, execute write and read 
operations in item (e) . 

Be sure to take apart the common screwdriver from the head pad 
during write or read operation. 
Note: Be careful not to push the head pad strongly with the common 

screwdriver. Also do not touch the pad surface to which a 

disk will be in contact. 

ii) After turning the pad position around 360", set th^ position again 
to the position where the highest read level was obtained. Then 
execute items (e) through (h) at the innermost track. 

iii) Continue the operation until the items (h) and (j) are sufficiently 
satisfied. Following causes are assumed for the insufficient 
result in item (h) or (j) after fine adjustment of the pad 
position. 



- 4075 - 



Q Inferior head pad: 

Replace the pad according to item 4-5-9. 

® Inferior disk: 

Disk and/or jacket is deformed or damaged. Replace the work 
disk with a new one. 

Q> Inferior pressure of the jacket pads: 

The jacket pad attached under the set arm (see Fig. 506, No. 8, 9A 
and 9B) does not touch the disk jacket surface. If item (h) is 
improved when the jacket surface is touched by a common screwdriver 
very lightly, execute the adjustment of the clamp arm position 
according to item 4-4-2, or replace the pad 9B to P/N 16787076-02 
(Disk pad 2.5t) . 

Caution: If the jacket surface is excessively pressed, it might be 
deformed or the spindle motor might be overloaded because 
of increasing the rotation torque. If item Q is done, 
measure the 4-12V current consumption of the FDD and confirm 
that the current does not exceed 300mA by an DC clip-on 
ammeter. For a commercially available general disks, the 
desirable current is 250mA, Max. 

@ Inferior head: 

Replace the head carriage Ass'y according to item 4-5-1. 

iv) Remove the work disk and apply a drop of locking paint around the 
rotating area of the head pad. Be careful not to smear the groove 
for common screwdriver with the locking paint. 

Possible causes for the insufficient head touch in a double sided FDD: 

Following causes are assumed for the insufficient result in items (h) 
through (j) on a double sided FDD. 

i) Inferior disk: 

Disk and/or jacket is deformed or damaged. Replace the work disk 
with a new one. 



- 4076 - 




(FiQ.425) Adjustment of head pad position (single sided FDD) 

ii) Inferior head flexture: 

Because of the failed performance of the arm lifter in item 4-4-4 
(model with head load solenoid) or the failed performance of the 
CSS Ass'y in item 4-4-5 (CSS model without head load solenoid), 
the flexture on which the head piece is located may be deformed - 
Remove the disk. Then open and close the front lever slowly to 
observe the gap between the side 1 and side heads from the front 
bezel. If the two head surfaces are not in parallel each other, 
it is considered to be the deformation ^ 

Replace the head carriage Ass'y according to item 4-5-1. 

iii) Inferior pressure of the jacket pads: 
Refer to item (k) -iii) - ® © and "Caution". 



- 4077 - 



(2) SKA method 

(a) Connect the SKA according to item 4-2-4 and set the FD PWR switch to 
the PSA side. 

(b) Start the spindle motor by key "5", (MON indicator turns on). 
Install a work disk and execute drive select by key "0". (DSO 
indicator turns on) . 

(c) Key in "CO" and confirm that the TRACK indicator becomes "00". 
(RECALIBRATE) 

(d) Key in "CI" (SEEK TMAX) 

(e) Key in "D3". (WRITE/READ LEVEL PRE 2F) 

(f) Write 2F and read operations are repeated. 

The DATA indicator Mill (mV) indicates the average read level 

of TP7 and TPS (Pre-amp. ) after each cycle of operation (one rotation 

of write and one rotation of read) is finished. 

(g) Observe the DATA indicator I I I I I (mV) with a slight depression 
(very slight depression easy to release: 10 % 20g) by a finger on 
the top of the upper head (double sided) or of the pad arm (single 
sided) . 

(h) Confirm that the read level measured in item (f) is more than 80% of 
that in item (g) . 

(i) For a double sided FDD, depress "F" key to stop and then depress 

"4" key to execute items (e) through (h) for side and side 1 heads 
respectively. The side is changed alternately by a depression of 
"4" key. If side 1 is selected, SIDE 1 indicator of the SKA turns, 
on. 



- 407 8 - 



(j) Key in "CO" (RECALIBRATE) and execute items (e) through (i) in the 

OJ.iU-i-J.li- . 

(k) Head touch adjustment for a single sided FDD: 
Refer to item (k) of "General method". 

+12V current consumption in item (k)-iii), "Caution" should be as 
follows. 

i) Stop all the commands already input by depressing "F" key. 
ii) Key in "OF". (+12V CURRENT) 
iii) Measure the +12V current consumption at that time by the DATA 
indicator Mill (mA) . 
iv) Key in "F" after the measurement completes. (STOP) 

(L) Possible causes for the inferior head touch in a double sided FDD: 
Refer to item (L) of "General method". 



- 4079 - 



4-4-10. Check and Adjustment of Asymmetry 



(A) Equipment 

(1) Work disk 

(2) SKA or user's system 

(3) Oscilloscope 

(B) Check and adjustment procedure 
(1) General method 

(a) Connect an oscilloscope to TPS (Read data) on the PCBA MFD control 
or to the READ DATA interface line. 

Oscilloscope range FD-55A a. F: DC mode, 2V,lysec 

FD-55G : DC mode, 2V, O.Susec 

(b) Start the spindle motor and install a work disk. 

(c) Set the head to the innermost track. 

(d) Execute head loading. 

(e) Execute IF write operation (125KHz of WRITE DATA frequency for 
FD-55A % F, 250KH2 for FD-55G) . 

(f) Measure the asymmetry referring to Fig. 426. 

Note: Oscilloscope should be so set that three read data pulses can be 
observed. Asymmetry width should be measured at the second read 
data pulse from the trigger pulse. 

(g) Confirm that the asymmetry is within the following range. 
Innermost track IF asymmetry FD-55A F: 0.6usec, Max. 

FD-55G : 0. 3psec , ^Max. 
- 4080 - 



TPS (Read data) J [ 



READ DATA 



n 








1 


J.. 

j Asymmetry 




IF interval 



Trigger 

(Fig. 426) Measurement of asymmetry 

(h) For a double sided FDD, execute items (e) through (g) for side 
and side 1 heads respectively. 

(i) If the value in item (g) or (h) is out of the specified range, adjust 
according to the following procedure. 

The adjustment can be done only for the PCBA versions or the PCBA 
revision numbers with the variable resistor R5 on the PCBA MFD control, 
No adjustment can be done without R5. 

i) Adjust the variable resistor R5 so that the asymmetry takes the 
minimum value while repeating IF write and IF read operations 
alternately. 

ii) For a double sided FDD, repeat the operation in item i) for 

side and side 1 heads alternately. The variable resistor shall 
be so adjusted that both asymmetry for side 1 and side heads 
take the minimum value. 

(j) If the values in items (g) and (h) are out of the specified range 
in the PCBA without the variable resistor R5, or if the adjustment 
in item (i) cannot be done sufficiently even if R5 is mounted, 
following causes are assumed. 



i) Leakage flux density in the environmental condition of the FDD 



- 4081 - 



is high: 

If there is some flux source near the FDD such as magnet, 
transformer, motor, Brovm tube, magnetized iron plate, etc., take 
it apart from the FDD. Then measure the asymmetry and adjust again. 

ii) Inferior disk: 

Replace the work disk, 
iii) Inferior head: 

Replace the head carriage Ass'y according to item 4-5-1. 

iv) Inferior PCBA MFD control: 

Replace the PCBA according to item 4-5-8 . 



- 4Q82 - 



(2) SKA method 

(a) Connect the SKA according to item 4-2-4 and set the FD PWR switch 
the PSA side. 

(b) Key in "BlF" . (IF DUTY) 

(c) Connect an oscilloscope to the DOUT terminal of the SKA. 
Oscilloscope range FD-55A 'x^ F: DC mode, 2V, 0.2ysec 

FD-55G : DC mode, 2V, O.ljisec 

(d) Start the spindle motor by key "5". (MON indicator turns on). 

(e) Install a work disk. 

(f) Execute drive select by key "0". (DSO indicator turns on). 

(g) Key in "CO" and confirm that the TRACK indicator becomes "00". 
(RECALIBRATE) 

(h) Key in "CI". (SEEK TMAX) 

(i) Key in "04". (WRITE/READ LEVEL PRE IF) 
(j) Measure the asymmetry as in Fig. 427. 



SKA DOUT 



II 






Asymmetry 


lVis,approx. . 





(Fig. 427) Measurement of asymmetry (SKA^ 



- 4083 - 



Confirm that the asymmetry is within the following range. 
Innermost track IF asymmetry FD-55A F: 0.6usec, Max. 

FD-55G : 0.3usec, Max. 

For a double sided FDD, depress "4" key and execute items (i) through 
(k) for side and side 1 heads respectively. The side is changed 
alternately by a depression of "4" key. If side 1 is selected, SIDE 1 
indicator of the SKA turns on. 

If the value in item (k) or (L) is out of the specified range, adjust 
according to the following procedure. The adjustment can be done 
only for the PCBA versions or the PCBA revision numbers with the 
variable resistor R5 on the PCBA MFD control. No adjustment can be 
done without R5. 

i) Adjust the variable resistor R5 so that the asymmetry takes the 
minimum value by keying in "D4". 
li) For a double sided FDD, execute the operation in item i) for both 
sides alternately by chainging the side by key "4". The variable 
resistor shall be so adjusted that both asymmetry for side 1 and 
side heads take the minimum value. 

If the values in items (K) and (L) are out of the specified range in 
the PCBA without the variable resistor R5, or if the adjustment in 
item (m) cannot be done sufficiently even if R5 is mounted, refer 
to item (j) of "General method". 



- 4084 - 



4-4-11. Check of Read Level 



(A) Equipment 

(1) Level disk 

(2) SKA or user's system 

(3) Oscilloscope (not required when the SKA is used) 

(B) Check procedure 
(1) General method 

(a) Use two channels of an oscilloscope and connect them to TP9 and TPlO 
(Differentiation amp.) on the PCBA MFD control. 

Oscilloscope range 48tpi : AC mode, 0.5V 

96tpi: AC mode, 0.2V 
Set both channels, 1 and 2 to the above range. Set either of the 
channels to Invert mode and ADD both channels. 

(b) Start the spindle motor and install a level disk. 

(c) Make the head move to the innermost track. 

(d) Execute head loading. 

(e) Execute 2F write operation for one rotation of the disk (250KHz of 
WRITE DATA frequency for DD-55A % F, SOOKHz for FD-55G) . 

(f) Measure the average amplitude (Vp-p) of the read waveform as in 
Fig. 428. 

(g) Calculate the read level by substituting the following expression 
with the measured value in item (f) and READ LEVEL calibration 
value (see level disk label). 

- 4085 - 



Read level (true value) = Measured value x 



100 



Calibration value 



TP9,TP1Q (ADD 




Vp-p 



(Fig. 428) Measurement of average read level (2F) 



(h) Confirm that the true value of the read level is within the following 
range . 

Innermost track read level 48tpi: l-4Vp-p, Min. 

96tpi: 0.6Vp-p, Min. 

(i) For a double sided FDD, execute items (e) through (h) for side 
and side 1 heads respectively. 

Cj) If the value in item (h) or (i) is out of the specified range, 
following causes are assumed. 

i) Inferior disk: 

Disk and/or jacket is deformed or damaged. Replace the level disk 
with a new one. 
ii) Abnormal disk rotational speed: 

Check and adjust according to item 4-4-7. 
iii) Inferior head touch: 

Check and adjust according to item 4-4-9. 
iv) Inferior head: 

Replace the head carriage Ass'y according to item 4-^5-1. 
v) Inferior PCBA MFD control: 

Replace the PCBA MFD control according to item 4-5-7. 



- 4086 - 



(k) Eject the level disk and release the Invert and ADD modes of the 
oscilloscope . 



- 4087 - 



(2) SKA method 



(a) Connect the SKA referring to item 4-2-4 and set the FD PWR switch 
to the PSA side. 

(b) Start the spindle motor by key "5", (MON indicator turns on). 

(c) Install a level disk. 

(d) Execute drive select by key "0". (DSO indicator turns on). 

(e) Key in "CO" and confirm that the TRACK indication becomes "00". 
(RECALIBRATE) 

(f) Key in "CI". (SEEK TMAX) 

(g) Key in "t)7". (WRITE/READ LEVEL DIP 2F) 

Calibration value of the level disk should be set previously in the 
SKA. 

(h) Confirm that the DATA indicator I I I 1 I (mVo-p) indicates the value 
within the following range. 

Innermost track read level 48tpi : 700mVo-p, Min. 

96tpi, 300mVo-p, Min. 

{i)-For a double sided FDD, depress key "4" and execute items (g) and (h) 
for side and side 1 heads respectively. The side is changed 
alternately by a depression of "4" key. If side 1 is selected, 
SIDE 1 indicator of the SKA turns on. 

(j) If the value in item (h) or (i) is out of the specified range, refer 
to item (j) of "General method". 

(k) Eject the level disk. 



- 4088 - 



4-4-12. Check of Resolution 

(A) Equipment 

(1) Level disk 

(2) SKA or user's system 

(3) Oscilloscope (not required when the SKA is used) 

(B) Check procedure 
(1) General method 

(a) Use two channels of an oscilloscope and connect them to TP7 and TPS 
(Pre-amp.) on the PCBA MFD control. 

Oscilloscope range 48tpi: AC mode, 50mV O.lV 

96tpi: AC mode, 20mV % 50mV 
Set both channels, 1 and 2 to the above range. Set either of the 
channels to Invert mode and ADD both channels. 

(b) Start the spindle motor and install a level disk. 

(c) Make the head move to the innermost track. 

(d) Execute head loading. 

(e) Execute IF write operation for one rotation of the disk <12-5KHz of 
WRITE DATA frequency for FD-55A 'V' F, 250KHz for FD-55G) . 

(f) Measure the average amplitude (VlF) as in Fig. 429 w 

(g) Execute 2F write operation as in item (e) (double in frequency to 
that in item (e) ) . 

(h) Measure the average amplitude (V2F) as in Fig -429. 



- 4089 - 



TP7,TP8 (ADD) 




V2F 



IF 



2F 



(Fig. 429) Measiirement of resolution 



(i) Calculate the resolution by substituting the following expression 
with the measiired values VlF, V2F, and RESOLUTION calibration value 
(see level disk label) . 

Resolution (true value) = V2F/V1F x 100/Calibration value (%) 

(j) Confirm that the true value is within the following range. 
Innermost track resolution: 55%, Min. 

(k) For a double sided FDD, execute items (e) through (j) for side 
and side 1 heads respectively. 

(L) If the value in item (j) or (k) is out of the specified range, 
following causes are assumed. 

i) Inferior disk: 

Disk and/or jacket is deformed or damaged. Replace the level 
disk with a new one. 
ii) Inferior disk rotational speed: 

Check and adjust according to item 4-4-7. 
iii) Inferior head touch: 

Check and adjust according to item 4-4-9. 
iv) Inferior head: Replace the head carriage Ass'y according to -item 



4-5-1. 



V) 



Inferior PCBA MFD control: 



- 4090 - 



Replace the PCBA MFD control according to item 4-5-7. 

(m) Eject the level disk and release the Invert and Add modes of the 
oscilloscope . 



- 4091 - 



(2) SKA method 

(a) Connect the SKA referring to item 4-2-4 and set the FD PWR switch 
to the PSA side. 

(b) Start the spindle motor by key "5". (MON indicator turns on). 

(c) Install a level disk. 

(d) Execute drive select by key "0", (DSO indicator turns on). 

(e) Key in "CO" and confirm that the TRACK indication becomes ."00". 
(RECALIBRATE) 

(f) Key in "CI". (SEEK TMAX) 

(g) Key in "D8" (RESOLUTION) 

The calibration value of the level disk should be set previously in 
the SKA. 

(h) Confirm that the DATA indicator I 1 I I I .(%) indicates the value 
within the following range. 

Innermost track resolution: 55%, Min. 

(i) For a double sided FDD, depress key "4" and execute items (g) and (h) 
for side head and side 1 head respectively. The side is changed 
alternately by a depression of "4" key. If side 1 is selected, 

SIDE 1 indicator of the SiCA turns on. 

(j) If the value in item (h) or (k) is out of the specified range, refer 
to item (L) of "General method". 

(k) Eject the level disk. 



- 4092 - 



4-4-13. .Check and Adjustment of Track Alignment 



(A) Equipment 



(1) Cross point screwdriver, M3 

(2) Alignment disk 

(3) Alignment adjustment jig or M3 screw of 15mm long 

(4) SKA or user's system 

(5) Oscilloscope 

(6) Hygrometer. 

(7) Locking paint 



(B) Check and adjustment procedure 

Note: Check and adjuslnnent of track alignment should be done in an 

environment of general room temperature and humidity. Even if the 
environmental condition is within the specified operational condition, 
extreemly high or low temperature, or extreemly high or low humidity 
should be avoided. Check and adjustment should be done after two 
hours, Min. of storing in the above mentioned condition. 
It is recommended that the orientation of the FDD for the track 
alignment check is the same as when the FDD is actually installed 
in the user's system. 



(1) General method 

(a) Use two channels of an oscilloscope and connect them to TP9 and TPlO 
(Differentiation amp.) on the PCBA MFD control. Also connect 
the external trigger of the oscilloscope to TP4 (Index) and apply 
positive trigger. 

Oscilloscope range 48tpi: AC mode, 0.5V, 20msec 

96tpi: AC mode, 0.2V, 20msec 
Set both channels, 1 and 2 to the above range. Set either of the 
channels to Invert mode and Add both channels. 



- 4093 - 



(b) Start the spindle motor and install an alignment disk. 

(c) Execute head loading. 

(d) Set the head to the following alignment check track. 
48tpi: track 16 

96tpi: track 32 

(e) Confirm that two lobe patterns as in Fig. 430 can be observed (it is 
not necessary that the levels of VA and VB are equal) . 

If only one lobe pattern can be observed or if two lobes become one 

pattern, the head is not on the alignment check track. 

In such event, execute step-out or step-in as mentioned below to 

obtain the most similar waveform to that in Fig. 430. 

48tpi: 2 tracks 

96tpi: 4 tracks 

Note: The above number of tracks to be stepped is required to make the 
alignment track position be fit with the magnetized condition of 
the basic magnetized phase "A" of the stepping motor. If the 
stepped track numbers are inassured, set it again from track 00 
(TRACK 00 output signal becomes TRUE) . 

For a 48tpi FDD, the lobe pattern as in Fig. 430 should be observed 
at the track of even number. For a 96tpi FDD, the lobe pattern 
should be observed at the track of multiple number of four (4). 

(f) After one or several step-outs from the check track, step in the 
head to the check track again and measure VA and VB at that time. 

(g) Calculate the true value of misalignment by substituting the value 

in item (f) and ALIGNMENT calibration value (see alignment disk label, 
attention to the side) . 



- 4094 - 



48tpi 




96tpi 




(Fig. 430) Alignment check lobe pattern 



Misalignment (true value) = 



VA-VB 



xlOO 



Larger value in VA & VB 
-Calibration value) - (Relative humidity-50) x K 



K is humidity compensation factor - 
48tpi: K=0-26 
96tpi: K=0.42 

e.g. VA=0.58V, VB=0.61V, Calibration value=-6(%). 
Relative humidity=65% , 96tpi: 

Misalignment (true value) ={ ^'^^ 61^'^"^ ^ 100- (-6)} - (65-50) 

X 0.42=^-5.2 (%) 

If the calculated value is positive, the magnetic head is shifted 
inward from the reference position, while the head is shifted outward 
from the reference position when the value is negative. 

(h) Conversely, measure VA and VB when the head is on the alignment check 
track by stepping-out after one or several step-ins. 

(i) Calculate the true value of misalignment as described in item (g) . 



- 4095 - 



(j) Confirm that both of the calculated values in items (g) and (i) are 
within the following range. 
True value of misalignment: 30%, Max. 

(k) For a double sided FDD, execute items (d) through (j) for side 
and side 1 heads respectively. 

(L) If the value in item (j) or (k) is out of the specified range, adjust 
the track alignment according to the following procedure: 

i) Loosen two fixing screws of the stepping motor a little, 
ii) Insert the alignment adjustment jig or M3 screw from the back 
side of the FDD as shown in Fig. 431. 
iii) Repeat step-in and step-out operations and adjust the misalignment 
to be the smallest on the alignment check track during both 
step-in and step-out operations by turning the jig or the screw 
(stepping motor moves little by little) . 

Note: When you adjust the alignment by observing the lobe pattern 

using the oscilloscope, pay attention to the calibration value 
on the alignment disk label and the ambient relative humidity. 

©Calibration value + (Relative humidity - 50) x K >: 0: 

When the left side lobe pattern level, VA is assumed as "1", 
lobe pattern ratio should be so adjusted that the right side 
lobe pattern level VB takes the following value: 

VB = 1 - Calibration value + (Relative humidity - 50) x K 

100 

(2) Calibration value + (Relative humidity - 50) x K £ 0: 

When the right side lobe pattern level, VB is assumed as "1", 
lobe pattern ratio should be so adjusted that the left 'side 
lobe pattern level VA takes the following value. 



- 4096 - 



Calibration value + (Relative humidity -50) x K 

VA = 1 



e.g. Calibration value = -6%, Relative humidity = 35%, 96tpi: 

-6+{35-50)x0.42=-12.3 < 

-6^(35-50)x0.42 ^ 3 
100 

Therefore, the target value of VA when VB is assumed as "1" 
is 0.88. 

iv) For a double sided FDD, repeat the adjusting operation in item 
iii) alternately for side and side 1 heads until the both 
misalignment take the smallest value . 
v) Tighten the two fixing screws of the stepping motor little by little 
for adjusting the true value of misalignment after tightening 
the screws with the specified torque to be within ±20%. 
vi) Remove the alignment disk, 
vii) Apply a drop of locking paint to the head of the stepping motor 
fixing screws. 

viii) Check and adjust the track 00 sensor according to item 4-4-14. 
ix) Check and adjust the track 00 stopper according to item 4-4-15. 

(m) Release the Invert and Add modes of the oscilloscope. 



- 4097 - 



stepping motor 



Alignment adjustment jig 



(Fig. 431) Adjustment track alignment 



- 4098 - 



(2) SKA method 



(a) Connect the SKA referring to item 4-2-4 and set the FD PWR switch 
to the PSA side , 

(b) Use two channels of an oscilloscope. Connect the 1st channel to the 
DOUT terminal of the SKA and the 2nd channel to the DIF teiminal of 
the SKA. Apply positive trigger by DOUT terminal. 

Oscilloscope range 

The 1st channel: DC mode, 2V, 20msec 

The 2nd channel 48tpi: AC mode, IV, 20msec 

96tpi: AC mode, 0.5V, 20msec 

(c) Key in "B9F" (INDEX observation) 

(d) Start the spindle motor by key "5". (WON indicator turns on). 

(e) Install an alignment disk. 

(f) Execute drive select by key "0". (DSO indicator turns on). 

(g) Key in "CO" and confirm that the TRACK indicator becomes "00". 

(RECALIBRATE) 

(h) Set the head to the alignment check track. 

48tpi: Key in "C2 16" and confirm that the TRACK indication becomes 
"16", 

96tpi: Key in "C2 32" and confirm that the TRACK indication becomes 
"32" . 

(i) Confirm that two lobe patterns as in Fig. 4 30 can be observed by the 
oscilloscope (it is not necessary that the levels of VA and VB are 
equal) . 



- 4099 - 



If only one lobe pattern can be observed or if two lobes become one 
pattern, the head is not on the alignment check track. 
In such event, execute step-in or step-out as follows to obtain the 
most similar waveform to that in Fig. 430. Step operation can be 
done by key "8" (STEP-IN) and key "9" (STEP-OUT) . By a depression 
of these keys, head will move for one track space. 
48tpi : 2 tracks 
96tpi: 4 tracks 

Note: The above number of tracks to be stepped is required to make the 
alignment track position be fit with the magnetized condition of 
the basic magnetized phase "A" of the stepping motor. 
For a 48tpi FDD, the lobe pattern as in Fig. 430 should be observed 
at the track of even number. For a 96tpi FDD, the lobe pattern 
should be observed at the track of multiple number of four (4) . 

(j) For a 96tpi, confiinn that the H GAIN indicator of the. SKA turns on 
in order to improve the measurement accuracy and switching of 
humidity coefficient. If it is off, turn it on by depressing "DD" 
key . 

(k) Key in "E3" (ALIGNMENT) 

Calibration value of the alignment disk and environmental relative 
humidity should be set previously in the SKA. 

(L) Confirm all the indications on the DATA I 1 I I I (%) indicator are 
within ±30%. 

The initial digit of the DATA indicator is the symbol . r (+) mark 
indicates that the head is shifted inward from the reference position, 
while - mark indicates that the head is shifted outward. 

(m) For a double sided FDD, execute the same check for side 1 head 
according to the following procedure . 



- 4100 - 



i) Key in "0" following the operation of item (L) (during execution 
of E3 command) and confirm that SIDE 1 indicator of the SKA turns 
on . 

ii) Confirm as in item (L) . 
Note: In order to change the head to side 0, key in "0" again. 
(SIDE 1 indicator turns off) . 

(n) Depress "F" key (STOP) . 

(o) If the value in items (L) or (m) is out of the specified range, adjust 
the track alignment according to the following procedure. 

i> Loosen the two fixing screws of the stepping motor a little, 
ii) Insert the alignment adjustment jig or M3 screw from the back 
side of the FDD as shown in Fig. 431. 
iii) Key in "E3" and adjust the jig or M3 screw so that the DATA 

indicator i i i { i (%) shows the smallest value. The stepping motor 
moves little by little when the jig or the screw is turned, 
iv) For a double sided FDD, repeat the adjusting operation in item iii) 
alternately for side and side 1 heads until the both misalignment 
take the smallest value, 
v) Tighten the two fixing screws of the stepping motor little by 

little to obtain the value within ±20% on the DATA indicator when 
the screws are tightened with the specified torque, 
vi) Remove the alignment disk, 
vii) Apply a drop of locking paint to the screw head of the stepping 
motor fixing screws, 
viii) Check and adjust the track 00 sensor according to item 4-4-14. 
ix) Check and adjust the track 00 stopper according to item 4-4-15. 

(p) Release the Invert and Add modes of the oscilloscope. 



- 4101 - 



4-4-14. Check and Adjustment of Track 00 Sensor 



(A) Equipment 

(1) Cross point screwdriver, M3 

(2) Work disk 

(3) Alignment disk 

(4) SKA or user's system 

(5) Oscilloscope (or digital volt meter) 

(6) Locking paint 

(B) Check and adjustment procedure 
(1) General method 

(a) Connect a digital volt meter or an oscilloscope to TPl (Track 00 
sensor) on the PCBA MFD control. 

Oscilloscope range: DC mode, IV 

(b) Start the spindle motor and install a work disk. 

(c) Execute head loading 

(d) Confirm that the voltage at TPl is within the following range when 
the head is set to track 00. 

Track 00 position TPl voltage: 3V, Min. 

(e) Turn the power off of the FDD and then turn it on again. Confirm 
that the stop position of the head carriage did not change at power 
off and on. This item aims to confirm that the track 00 position 
matches the basic magnetized phase A of the stepping motor. 

(f) Make the head move to the following track. 



- 4102 - 



48tpi: 02 track 

t^r I i r\ A I _i, 

(g) Confirm that the voltage at TPl 
the track position in item (f ) , 
TPl voltage at track 02 (48tpi) 



is within the following range at 
or track 04 (96tpi) : 0.5V, Max. 



(h) If the value in item (d) , (e) , or (g) is out of the specified range, 
adjust the position of the track 00 sensor according to the following 
procedure . 

i) Loosen the fixing screw of the track 00 stopper (see Fig. 434) and 
shift the stopper in the step-out direction (make apart from the 
rear side of the head carriage) . 
ii) Connect the oscilloscope to TP9 or TPIO (Differentiation amp.) 
of the PCBA MFD control. 

Oscilloscope range: AC mode, 0.2V, 20msec 
iii) Install an alignment disk. The track alignment should be adjusted 
correctly according to item 4-4-13. 
iv) Make the head move to the position where the lobe pattern as in 
Fig. 430 can be observed, 
v) Remove the alignment disk, 
vi) Connect the digital voltmeter or the oscilloscope to TPl (Track 00 
sensor) on the PCBA MFD control. 
Oscilloscope range: DC mode, IV 
vii) Step out the head for the following track space from the position 
where the normal lobe pattern is observed. 
48tpi: 15 tracks (head will be on track 01) 
96tpi: 30 tracks (head will be on track 02) 
viii) Install a work disk. 

ix) Loosen the fixing screws of the track 00 sensor (see Fig. 432) 
and move the sensor a little so that the voltage at TPl falls 
within the following range. 

TPl voltage at track 01 (48tpi) , track 02 (96tpi) : 



- 4103 - 



0.5 3V (0.3 1.2V, approx. center) 
x) Confirm the items (d) through (g) . 
xi) Adjust the track 00 sensor position so that the values in items 
(ix) and (x) satisfy the specification when the screw has been 
tightened with the specified torque, 
xii) Apply a drop of locking paint on the fixing screw head, 
xiii) Adjust the track 00 stopper according to item 4-4-15. 




(Fig. 432) Adjustment of track 00 sensor 



- 4104 - 



(2) SKA method 



(a) Connect the SKA referring to item 4-2-4 and set the FD PWR switch 
to the PSA side. 

(b) Use two channels of oscilloscope and connect them as follows. 

i) The 1st channel: SKA DOUT terminal 

DC mode, 5V, 5 '^^ 10msec 
ii) The 2nd channel: PCBA MFD control TPl (Track 00 sensor), IV range 
iii) External trigger: DIRECTION SELECT interface signal (Interface 

connector pin No. 18) or Pin 3 of J3 (resistor 
network RAl for terminator) on the PCBA MFD 
control . 
(+) trigger - 

(c) Key in "B8 F" . (STEP observation) 

(d) Start the spindle motor by key "5". (MON indicator turns on). 

(e) Install a work disk. 

(f) Execute drive select by key "0". (DSO indicator turns on), 

(g) Set the step rate and the settling time as follows referring to item 
4-2-4-3. 

48tpi: Step rate 6msec, Settling time 15msec 
96tpi: Step rate 3msec, Settling time 15msec 

(h) Key in "CO" and confirm that the TRACK indicator becomes "00". 

(i) Key in "C5". (TOO TIMING, SEEK ±5) 

(j) Measure the timing of points A and B and the voltages VL and VH 



- 4105 - 



referring to Fig. 433. The values should be with the following 
range . 

TPl clip timing. A: tA in Fig. 433. 
TPl clip timing, B: tB in Fig. 433. 
TPl voltage, VL: 0.5V, Max. 
TPl voltage, VH: 3V, Min. 



DIRECTION SELECT -p 
{External trigger) J 



Step-out 



SKA DOUT 



TPl 

(Track 00 sensor) 



1 2 3 4 5 

JUUUL 



VL 




48tpi FDD 



Step-in 



1 2 3 4 5 

JL 



VH 



tA 



3ms 



Track 00 detection 




tB 



3ms 



1 2 3 4 5 



SKA DOUT 



TPl 



XJUL 



VL 



\ 



(Track 00 sensor) 



96tpi FDD 



tA 



1 2 3 4 5 

111 



VH 



tB 



Track 00 detection 



Note: VL and VH shall be smooth without undulations 



(Fig. 433) Track 00 sensor output waveform 



(k) Key in "F". (STOP) 



- 4106 - 



(L) Turn the FD PWR switch of the SKA off at the track 00 position and 
then set it again to the PSA side. Confirm that the stop position 
of the head carriage did not change at power off and on. 

(m) If the value in item (j) or (L) is out of the specified range, adjust 
the position of the track GO sensor according to the following 
procedure . 

i) Loosen the fixing screw of the track 00 stopper (see Fig. 434) and 
shift the stopper in the step-out direction (make apart from the 
rear side of the head carriage) . 
ii) Connect the 2nd channel of the oscilloscope to TP9 or TPlO 

(Differentiation amp.) of the PCBA MFD control and change the 
trigger to this channel. 

Oscilloscope range: AC mode, 0.2V, 20msec 
iii) Install an alignment disk. The track alignment should be correctly 
adjusted according to item 4-4-13. 
iv) Key in "CO" and confirm that the track indicator becomes "00". 
(RECALIBRATE) . 

v) Key in the following code and confirm that two lobe patterns as in 
Fig. 4 30 can be observed. 
48tpi: C2 16 
96tpi: C2 32 

If normal lobe pattern cannot be observed, move the head to the 
track position where the typical lobe pattern can be observed by 
stepping in by key "8" or by stepping out by key "9". 
vi) Remove the alignment disk, 
vii) Key in the following code. (SET TRACK NUMBER) 
48tpi: E4 16 
96tpi: E4 32 
viii) Key in "C2 00" (SEEK 00) 

Don't key in "CO" (RECALIBRATE), 
ix) Change the connection of the oscilloscope as in item (b) . 
x) Key in "C5". (TOO TIMING SEEK ±5) 



- 4107 - 



xi) Loosen the fixing screw of the track 00 sensor (see Fig. 432) and 
adjust the sensor position where the requirements in item (j) are 
all satisfied. 

xii) Repeat the adjustment so that the values in item (j) fall within 
the specified range when the fixing screw has been tightened with 
the specified torque, 
xiii) Apply a drop of locking paint to the fixing screw head. 

xiv) Adjust the track 00 stopper according to item 4-4-15. 



- 4108 - 



4-4-15. Check and Adjustment of Track 00 Stopper 

(A) Equipment 

(1) Cross point scr-ewdriver , M3 

(2) SKA or user's system 

(3) Locking paint 

(B) Check and adjustment procedure 
(1) General method 

(a) Set the head to track 00. 

(b) Step out the head from the track 00 position. 

(c) Confirm that the head carriage does not move by the step-out command 
(head carriage rests on track 00) . 

(d) Confirm that the gap between the head carriage and the extreme end 
of the track 00 stopper is 0.1 'v* 0.4mm- (See Fig. 434) . 

(e) Repeat step-in and step=out operations between track 00 and track 05. 
Confirm that no impact sound cam be heard between the head carriage 
and the track 00 stopper. 

(f) Turn off the FDD power and depress the head carriage lightly against 
the track 00 stepper with fingers. (See Fig. 434) . 

(g) Confirm that the head carriage automatically returns to the initial 
position (track 00) when the power is turned on again. 

(h) If any one of the items (d) , (e) , and (g) is not satisfied, adjust 
the track 00 stopper position according to the following procedure. 



- 4109 - 



i) Set the head to track 00. 
ii) Loosen the fixing screw of the track 00 stopper. (See Fig. 434) . 
iii) Adjust the stopper position so that the gap between the stopper 
and the head carriage becomes 0.25inm, approx. And then tighten 
the screw with the specified torque . 
iv) Execute items (a) through (g) . 
v) Apply a drop of locking paint on the fixing screw head. 



Head carriage Ass'y 




0.25±0.15mm 



(Fig. 434) Adjustment of track 00 stopper 



- 4110 - 



(2) SKA method 

(a) Connect the SKA referring to item 4-2-4 and set the FD PWR switch to 
the PSA side. 

(b) Execute drive select by key "0". (DSO indicator turns on). 

(c) Key in "CO" and confirm that the TRACK indicator becomes "00". 
(RECALIBRATE) . 

(d) Set the step rate and the settling time as follows referring to item 
4-2-4-3. 

48tpi: Step rate 6msec, Settling time 15msec 
96tpi: Step rate 3msec, Settling time 15msec 

(e) Key in "9". (STEP OUT) 

(f) Confirm that the head carriage does not move even if "9" is keyed in 
(head carriage rests on track 00) . 

(g) Confirm that the gap between the head carriage and the extreme end 
of the track 00 stopper is 0.1 0.4ram. (See Fig. 434) . 

(h) Key in "CO" and key in "C5". (STEP TIMING, SEEK ±5) 

(i) Confirm that no impact sound can be heard between the head carriage 
and the track 00 stopper. 

(j) Turn off the FD PWR switch of the SKA and depress the head carriage 
lightly against the track 00 stopper. (See Fig. 434) , 

(k) Confirm that the head carriage automatically returns to the initial 

position (track 00) when the FD PWR switch is set to the PSA side again. 



- 4111 - 



(L) If any one of the items (g) , (i) , and (k) is not satisfied, adjust 
the track 00 stopper position according to the following procedure. 

i) Key in "CO" and confirm that the TRACK indicator becomes "00" 
(RECALIBRATE) 

ii) Loosen the fixing screw of the track 00 stopper. (See Fig. 434) . 
iii) Adjust the stopper position so that the gap between the stopper 
and the head carriage becomes 0.25mm, approx. 
And then tighten the screw with the specified torque, 
iv) Execute items (a) (k) . 
v) Apply a drop of locking paint on the fixing screw head. 



- 4112 - 



4-4-16. Check and Adjustment of Index Burst Timing 

(A) Equipment 

(1) Cross point screwdriver, M3 

(2) Alignment disk 

(3) SKA or user's system 

(4) Oscilloscope (not required when the SKA is used) 

(5) Locking paint 

(B) Check and adjustment procedure 
(1) General method 

(a) Use two channels of the oscilloscope. Connect the 1st channel to TP4 
(Index) on the PCBA MFD control and the 2nd channel to TP7 or TPS 
(Pre-amp.). Apply positive trigger by TP4. 

Oscilloscope rauige 

The 1st channel: DC mode, 2V, SOysec 

The 2nd channel 48tpi: AC mode, IV, SOysec 

96tpi: AC mode, 0.5V, SOysec 

(b) Start the spindle motor and install an alignment disk. 

(c) Execute head loading. 

(d) Set the head to the following track. 
48tpi: Track 01 

96tpi: Track 02 

(e) Measure "t" in Fig. 435. 

(f) Substitute the following equation with the measured value in item 
(e) and INDEX TIMING calibration value (see alignment disk- label) . 



- 4113 - 



TP 4 (Index) 



TP7 or TPS 




(Fig. 435) Index burst timing 



Index burst timing (true value) =Measured value - Calibration value (ys) 



Cg) Confirm that the true value of the index burst timing is within the 
following range . 
FD-55A F: 200±200psec 
FD-55G : 165±165nsec 



(h) If the value in item (g) is out of the specified range, adjust the 
index sensor Ass'y position according to the following procedure. 

i) Loosen the fixing screws (see Fig. 436) of the PCBA front OPT and 
adjust its position to make the true value of the index burst 
timing fall in the specified range in item (g) . 
ii) Repeat the adjustment so that the true value of the index burst 
timing falls in the range of item (g) when the fixing screw has 
been tightened with the specified torque, 
iii) Apply a drop of locking paint on the fixing screw head. 



(i) Remove the alignment disk. 



- 4114 - 




(Fig. 436) Adjustment of index sensor 



- 4115 - 



(2) SKA method 

(a) Connect the SKA referring to item 4-2-4 and set the FD PWR switch 
to the PSA side. 

(b) Start the spindle motor by key "5". (MON indicator turns on). 

(c) Install an alignment disk. 

(d) Execute drive select by key "0". (DSO indicator turns on). 

(e) Key in "CO" and confirm that the TRACK indicator becomes "00". 
(RECALIBRATE) 

(f) Set the head to the index check track. 

48tpi: Key in "C2 01" and confirm that the TRACK indication becomes 
"01". 

96tpi: Key in "C2 02" and confirm that the TRACK indication becomes 
"02". 

(g) Key in "E6". (INDEX TIMING) 

The calibration value of the index timing should be set previously 
in the SKA. 

(h) Confirm that the DATA indicator Mill (ys) indicates the value within 
the following range. 

FD-55A 'x. F: 200±200ysec 
FD-55G : 165±165ysec 

(i) Key in "F". (STOP) 

(j) If the value in item (h) is out of the specified range, adjust the 
index sensor Ass'y position according to the following procedure. 



- 4116 - 



i) Loosen the fixing screws (see Fig, 436) of the PCBA front OPT and 
its position so that the DATA indication under execution shows 
the median value in the specified range of item (h) . 
ii) Repeat the adjustment so that the DATA indication takes the median 
value when the fixing screw has been tightened with the specified 
torque . 

iii) Depress "F" key. (STOP) . 
iv) Apply a drop of locking paint on the fixing screw head. 

(k) Remove the alignment disk. 



- 4117 - 



5. MAINTENANCE PARTS REPLACEMENT 



5-1. Replacement of Head Carriage Ass'y 

(A) Tools 

(1) Cross point screwdriver, M3 

(2) Common screwdriver, small size 

(3) A pair of tweezers 

(4) Alcohol and gauze 

(5) Locking paint 

(6) SKA or user's system 

(7) Required equipment for each referring item 

(B) Replacement procedure 

(1) Disconnect the head connector (J9) and remove the head cable from the 
cable clamper B (Fig. 506, No. 15). 

(2) Remove the plate (Fig. 506, No, 12) and shift lever (Fig. 506, No. 14) on 
the set arm by removing their fixing screws (Fig. 506, Sll, S3). 

(3) Remove the set arm (Fig. 506, No. 7) by removing the two fixing screws 
(Fig. 506, S6) . 

(4) Remove two screws (Fig. 506, S3) fixing the head carriage Ass'y (Fig. 506, 
No. 24: the figure shows a double sided FDD) and the steel belt (Fig. 506, 
No, 28), and remove the steel belt and the belt spring (Fig. 506, No. 29) 
from the carriage. 

(5) Remove three screws (Fig. 506, S3, S4) to remove the spring guides A and 
B (Fig. 506, Nos. 25, 26) which fix two guide shafts (Fig. 506, No.24) . 

(6) Remove the head carriage Ass'y with the guide shafts. (See Fig. 437). 



- 4118 - 



(7) Install a new head carriage Ass'y and two guide shafts in the reverse 
order of items (1) through (6) . 

Notes: 1. When replacing the head carriage Ass'y, replace the guide shafts 
at the same time because of matching the hole diameter of the 
carriage with that of the guide shaft. Guide shafts are to be 
designated in combination with the head carriage Ass'y. (Refer 
to item 4-1-3; (3) ) . 

Guide shaft which goes through the hole of the head carriage 
smoothly with a little clearance is considered to be the best. 
2. If there is dust or dirt on the surface of the steel belt, belt 
spring, capstan, etc. clean them carefully with alcohol and 
gauze . 

(8) After finishing the installation of head carriage Ass'y, loosen the 
screw (Fig. 506, Si) which fixes the steel belt to the capstan of the 
stepping motor via the plate washer (Fig. 506, No. 30) . 

(9) After iwDving the head carriage several times manually, tighten the 
fixing screw of the steel belt in item (8) carefully with the specified 
torque. At this time, be careful that the belt is tensioned straightly. 
Pay attention not to damage the surface of the belt or the capstan. 

(10) Loosen the fixing screw (Fig. 506, S8) of the track 00 stopper (Fig. 506, 
No. 4) to shift the stopper toward the rear side of the FDD. 

(11) Adjust the set arm position according to item 4-4-1. 

(12) Check and adjust the clamp arm position according to item 4-4-2. 

(13) Check and adjust the front lever position according to item 4-4-3- 

(14) Check and adjust the arm lifter according to item 4-4-4. (Only for 
models with the head load solenoid) . 



- 4119 - 



(15) Check and adjust the CSS Ass'y according to item 4-4-5. (Only for the 
double sided CSS models) . 

(16) Execute head cable treatment according to item 4-2-3. 

(17) Make the head seek continuously between the track 00 and the innermost 
track and confirm that the steel belt does not meander nor undulate . 
When the SKA is used, key in "C6" for this check and key in "F" for 
stop. 

If there is some abnormal running of the steel belt, readjust the 
belt with two screws in item (4) and one screw in item (8) - After 
the adjustment tighten the screws carefully with the specified torque. 

(18) Check and adjust the head touch according to item 4-4-9. 

(19) Check and adjust the asymmetry according to item 4-4-10. (Adjustment is 
applied only for the models equipped with variable resistor, R5 on the 
PCBA MFD control) . 

(20) Adjust the track alignment according to item 4-4-13. 

(21) Adjust the track 00 sensor position according to item 4-4-14. 

(22) Adjust the track 00 stopper position according to item 4-4-15. 

(23) Check and adjust the index burst timing according to item 4-4-16. 

(24) Check for the read level according to item 4-4-11. 

(25) Check for the resolution according to item 4-4-12. 

(26) It is recommended to connect the FDD to the system for overall test. 
(Refer to item 4-2-5, (1)). 



- 4120 - 



4-5-2. Replacement of Stepping Motor Ass'y 

(A) Tools 

(1) Cross point screwdriver, M3 

(2) A pair of tweezers 

(3) Alcohol and gauze 

(4) Locking paint 

(5) SKA or user's system 

(6) Required equipment for each referring item 

(B) Replacement procedure 

(1) Disconnect the stepping motor connector { J6) . 

(2) Remove the cable holder (Fig, 506, No. 32) to make the stepping motor 
cable be free, 

(3) Remove two screws (Fig. 506, S3) fixing the head carriage Ass'y (Fig. 506, 
No. 24) and the steel belt (Fig, 506, No.28) , and remove the steel belt 
and the belt spring (Fig. 506, No. 29) from the carriage. 

(4) Remove the two fixing screws (Fig. 506, S7) of the stepping motor Ass'y 
(Fig. 506, No. 27) and remove the stepping motor with the steel belt. 

(5) Remove screw (Fig. 506, SI) on the capstan of the stepping motor and 
remove the steel belt and the plate washer (Fig. 506, No.30) . 

(6) Fix a new steel belt temporarily to the capstan of a new stepping motor 
with the plate washer and the screw in item (5) as they were. 

Notes: 1. Fundamentally, the steel belt and the belt spring should be 
replaced with the stepping motor. However, if there is no 
inferior points for these belt and spring, they may be used 



- 4122 - 



after cleaning the surface carefully with alcohol and gauze . 
2, Never renvove the olate of the steooing motor Ass'v since thev 
are combined each other. 

(7) Install the stepping notor in item (6) according to the reverse order 
of items (1) through (4) . 

(8) Loosen the screw which fixes the belt to the capstan. 

(9) After moving the head carriage several times manually, tighten the 
fixing screw of the steel belt in item (8) carefully with the specified 
torque. At this time, be carefull so that the belt is tensioned 
straightly. Pay attention not to damage the surface of the belt or 
the capstan. 

(10) Loosen the fixing screw (Fig. 506, S8) of the track 00 stopper (Fig. 506, 
No. 4) to shift the stopper toward the rear side of the FDD. 

(11) Make the head seek continuously between the track 00 and the innermost 
track and confirm that the steel belt does not meander nor undulate. 
When the SKA is used, key in "C6" for this check and key in "F" for stop. 
If there is some abnormal mnning of the steel belt, readjust the 

belt with two screws in item, (4) and one screw in item (8) . After 
the adjustment tighten the screws carefully with the specified torque. 

(12) If the steel belt is replaced, execute the continuous seek in i"tem (11) 
for five minutes, approx. 

(13) Adjust the track alignment according to item 4-4-13. 

(14) Adjust the track 00 sensor position according to item 4-4-14. 

(15) Adja^t th<5 traek OO stopper position according to item 4-^4-15. 



- 4123 - 



4-5-3. Replacement of DD motor Ass'y (Spindle Motor) 

(A) Tools 

(1) Cross point screwdriver, M3 

(2) Conunon screwdriver, small size 

(3) A pair of tweezers 

(4) Locking paint 

(5) SKA or user's system 

(6) Required equipment for each referring item 

(B) Replacement procedure 

(1) Disconnect the spindle motor connector (J7) . 

(2) Remove three screws (Fig. 506, S2, SIO) fixing the PCBA DD motor servo. 

(3) Remove three screws (Fig. 506, S5) of spindle side fixing the DD motor 
Ass'y and draw out the DD motor Ass'y from the rotor side (PCBA dide) . 

(4) Remove the spacer (Fig. 506, No. 6) from the PCBA DD motor servo. 

(5) Install a new DD motor Ass'y in the reverse order. 

Notes: 1. Be sure to attach the spacer (Fig. 506, No. 6) to the correct 

position. Spacer is made of insulation material and if it is 
not inserted, the electric circuit will be damaged. 

2. The spindle area of the DD motor (clamping cup of the disk) is 
precisely machined. For installing the motor to the frame, 
place the spindle in pallarel to the frame and push into the 
frame slowly. Handle the spindle very carefully not to damage 
the spindle surface. 

3. The, installation screw (Fig. 506, SIO) of the spacer is made of 
plastic. Metallic screw will damage the electric circuit. 



- 4124 - 



Do not tighten the plastic screw with larger torque than in 
specified in item 4— 2— i. 

(6) Arrange the DD motor cable be in space between the PCBA MFD control and 
the frame. 

(7) Adjust the set arm position according to item 4-4-1. 

(8) Check and adjust the clcunp arm position according to item 4-4-2. 

(9) Check for the file protect sensor according to item 4-4-6. 

(10) Adjust the disk rotational speed according to item 4-4-7. 

(11) Check and adjust the track alignment according to item 4-4-13. 

(12) Check and adjust the index burst timing according to item 4-4-16. 



- 4125 - 



4-5-4. Replacement of Collet Ass'y 

(A) Equipment 

(1) Cross point screwdriver, M3 

(2) A pair of tweezers 

(3) Round nose pliers 

(4) Locking paint 

(5) Required equipment for each referring item 

(B) Replacement procedure 

(1) Remove the plate (Fig. 506, No. 12) and the shift lever (Fig. 506, No. 14) 
on the set arm by removing their fixing screws (Fig. 506, Sll, S3). 

(2) Remove the set arm (Fig. 506, No. 7) by removing the two fixing screws 
(Fig. 506, S6) . 

(3) Remove the E-ring (Fig. 506, S15) which fixes the collet Ass'y (Fig. 506, 
No. 10) to the set arm and remove the collet and the spring (Fig -506, 
No. 11) . 

(4) Install a new collet Ass'y in the reverse order. Pay attention to the 
orientation of the spring. The spring is conical. The smaller 
diameter side faces the collet side and the larger diameter side faces 
the set arm side. 

(5) Adjust the set arm position according to item 4-4-1. 

(6) Check and adjust the clamp arm position according to item 4-4-2. 

(7) Check and adjust the track alignment according to item 4-4-13. 



- 4126 - 



4-5-5. Replacement of Head Load Solenoid 

This item applies only for the FDD with the head load solenoid. 

(A) Tools 

(1) Cross point screwdriver, M3 

(2) Hexagon wrench key, 1.5mm 

(3) A pair of tweezers 

(4) Locking paint 

(5) Required equipment to each referring item 

(B) Replacement procedure 

(1) Disconnect the head load solenoid and the track 00 connector (J4) . 

(2) Pull out two solenoid pins (terminal Nos. 1 and 2) from' the connector 
housing referring to item 4-2-2, (4) . 

(3) Remove two fixing screws (Fig. 506, S3) to remove the head load solenoid 
Ass'y (Fig. 506, No.23) . 

(4) Install a new head load solenoid Ass'y in the reverse order. 

Note: Arrange the wiring connection of the head load solenoid so that the 
white lead wire is connected to pin 1 and the red wire to pin 2. 
(See Fig. 439) . 

(5) Position the head load solenoid Ass'y so that the rod of <j)2mm be in 
parallel with the set arm. (See Fig. 438). 

And for a double sided FDD, the space between the head protector Ass'y 

and the arm lifter shall be more than 0.2mm. 

Then tighten the screws with the specified torque. 



- 4127 - 




Yellow (p 

Solenoid, lead wire 
Red (pin 2 ) 



Solenoid lead wire 

White (pin 1) 




Black (pin 6) 
Grey (pin 5) 



Polarizing key position 
(pin 3) 



(Fig. 439) Color identification of connector J4 wiring 



(6) Check and adjust the arm lifter according to item 4-4-4, 



- 4128 - 



4-5-6. Replacement of Track 00 Sensor Ass'y 



(A) Tools 



(1) Cross point screwdriver, M3 

(2) A pair of tweezers 

(3) Locking paint 

(4) SKA or user's system 

(5) Required equipment for each referring item 



(B) Replacement procedure 



(1) Disconnect the head load solenoid and the Track 00 connector (J4) . 



(2) Pull out two solenoid pins (terminal Nos. 1 and 2) from the connector 
housing referring to item 4-2-2, (4). 

(3) Remove the fixing screw (Fig. 506, S8) to remove the TOO sensor Ass'y 
(Fig. 506, No.22) . 

(4) Install a new TOO sensor Ass'y in the reverse order. 

Note: Arrange the wiring connection of the head load solenoid so that the 
white lead wire is connected to pin 1 and red wire to pin 2. (See 
Fig. 439) . 

(5) Loosen the fixing screw (Fig. 506, S8) of the track 00 stopper (Fig. 506, 
No. 4) to shift the stopper foward the rear side of the FDD. 

(6) Adjust the track 00 sensor position according to item 4-4-13. 

(7) Adjust the track 00 stopper position according to item 4-4-14. 



- 4129 - 



4-5-7. Replacement of PCBA MFD Control 

(A) Tools 

(1) Cross point screwdriver, M3 

(2) Conunon screwdriver, small size 

(3) SKA or user's system 

(4) Required equipment for each referring item 

(B) Replacement procedure 

(1) Disconnect all of the connectors connected to the PCBA MFD control 
(Fig. 506, No. 34) referring to item 4-2-4. 

(2) Remove the PCBA by removing the. three fixing screws (Fig. 506, S2) . 

(3) Install a new PCBA MFD control in the reverse order. 

(4) Set the straps and terminator as they were on the old PCBA. 

(5) Check for the file protect sensor according to item 4-4-6. 

(6) Check for the erase gate delay according to item 4-4-8. 

(7) Check and adjust the asymmetry according to item 4-4-10. 

(8) Check for the read level according to item 4-4-11. 

(9) Check for the resolution according to item 4-4-12. 

(10) Check for the track 00 sensor according to item 4-4-14. 

(11) Check for the index burst timing according to item 4-4-16. 

~ 4130 - 



(12) It is recommended to connect the FDD to the system for overall test. 
(Refer to item 4-2-5, (1) ) . 



- 4131 - 



4-5-8. Replacement of PCBA Front OPT 

(A) Tools 

(1) Cross point screwdriver, M3 

(2) SKA or user's system 

(3) Required equipment for each referring item 

(B) Replacement procedure 

(1) Disconnect PCBA front OPT connector (J5) . 

(2) Remove the two fixing screws (Fig. 506, S20) to remove the PCBA 

(3) Install a new PCBA front OPT in the reverse order. 

(4) Check for the file protect sertsor according to item 4-4-6. 

(5) Adjust the index burst timing according to item 4-4-16. 

(6) Check for the performance of the front bezel indicator. 



- 4132 - 



4-5-9. Replacement of Head Pad (Single sided only) 

This item applies only to the single sided FDD. 

(A) Tools 

(1) A pair of tweezers 

(2) Required equipment for each referring item 

(B) Replacement procedure 

(1) Lift up the pad arm manually and peel the pad carefully with a pair of 
tweezers. (See Fig. 440) . 

(2) Apply a new pad to the initial position. Be careful not to press the 
pad surface strongly. 

(3) Clean the magnetic head surface according to item 4-3-2. 

(4) Adjust the head pad position according to item 4-4-9. 

(5) Check for the read level according to item 4-4-11. 

(6) Check for the resolution according to item 4-4-12. 



- 4133 - 




(Fig. 440) Replacement of head pad 



- 4134 - 



4-5-10. Replacement of Front Bezel Ass'y 

(A) Tools 

(1) Cross point screwdriver, M3 

(2) Hexagon wrisnch key, 1.5mm 

(3) Required equipment for each referring item 

(B) Replacement procedure 

(1) Turn the front lever to close position and remove a fixing set screw 
(Fig. 506, S13) . 

(2) Turn the front lever to open position and remove another fixing set 
screw. Then draw out the front lever Ass'y {Fig. 506, No. 37). 

(3) Remove the fixing screws (Fig. 506, 37} of the front bezel Ass'y (Fig. 506, 
No. 36) and draw the front bezel out. 

(4) Install a new front bezel Ass'y in the reverse order. For the 
installation of the front bezel, press the longitudinal sides of the 
bezel against the frame and tighten the fixing screws with the 
specif xed torque. 

(5) Adjust the front lever position according to item 4-4-3. 



- 4135 - 



4-5-11. Replacement of Front Lever Ass'y 

(A) Tools 

(1) Hexagon wrench key, l.Siran 

(2) Required equipment for each referring item 

(B) Replacement procedure 

(1) Turn the front lever to close position and remove a fixing set screw 
(Fig.5Q6, S13) . 

(2) Turn the front lever to open position and remove another fixing set 
screw to draw out the front lever Ass'y (Fig. 506, No.37) . 

(3) Install a new front lever Ass'y in the reverse order. 

(4) Adjust the front lever position according to item 4-4-3. 



- 4136 - 



5-12. Replacement of CSS Ass'y 



This item applies only to the double sided CSS model {without head 
load solenoid) . 

(A) Tools 

(1) Cross point screwdriver, M3 

(2) Required equipment for each referring item 

(B) Replacement procedure 

(1) Remove the fixing screw (Fig. 506, S3) to remove the shift lever (Fig. 506 
No. 14) from the set arm. 

(2) Remove the fixing screw (Fig.506,S3) to remove the CSS Ass'y (Fig. 506, 
No. 39) from the frame. 



(3) Install a new CSS Ass'y in the reverse order. Be careful to install 
the arm lifter area {^2ma rod) and the shift lever be in parallel to 
the set arm. The CSS Ass'y should be fixed with no contact to the 
set arm- (See Fig. 441). 

(4) Check for the CSS Ass'y according to item 4-4-5. 



- 4137 - 




- 4138 - 



SECTION 5 



DRAWINGS & PARTS LIST 



- 500 - 



5-1. CONFIGURf^TION 



Following shows the configuration of the main parts of FD-55 (L) - (Refer 
to Fig. 501 Fig. 505) . Refer to items 5-2 and 5-3 as to detailed break- 
downs . 



-Transport 



-Frame 

-DD motor Ass'y (Spindle motor) 

— Stepping motor Ass'y 

— Set arm Ass'y —Collet Ass'y 



■Holder Ass'y 



-TOO sensor Ass'y 
— *1 Head load solenoid Ass'y 
— *2 Head protector Ass'y 
— *3 CSS Ass'y 
— Front bezel Ass'y 
— Front lever Ass'y 
— Head C3rriag'=» Ac;c:'y 
— PC3A MFD control 
— PC3A front OPT 
I — *4 Optional assemblies 



-Lever shaft Ass'y 
' — Clamp arm Ass ' y 



Notes: *1: Applied only for models with head load solenoid (single and 
double sided) . 

*2: Applied only for double sided models withe head load solenoid. 
*3: Applied only for double sided CSS models. 
*4: Refer to separate materials (SECTION 6) . 



(Table 501) Main parts configuration of FD-55 (L) 



- 501 - 



PCBA fixing screws 



Front bezel Ass'y 



Front lever 
Ass'y 



File protect sensor 
Index sensor 



Collet Ass'y 



PCBA front OPT 




J5(PCBA front OPT) 

J9 (Head) 

Cord guide 

4 (Head load 
solenoid & TOO) 



Set arm Ass'y 



J2 (Power) 



Cable clamper B 



JKSignal interface, 
card edge) 



Frame ground terminal 



(Fig -501) External view (No.l) 



- 502 - 



Spindle (DD motor Ass'y) 



Index sensor (LED) 



Lever shaft 
Ass ' y 



Front 
lever 
fixing 
screw 



DD motor Ass'y fixing screws 



Head carriage Ass'y 



*Head protector Ass'y 
or CSS Ass'y 



^ead load solenoid 
Ass ' y 




Clamp arm Ass' y 



TOO sensor Ass'y 



Stepping motor Ass'y 



Head caible 



Note: Refer to Table 501 as to the assemblies with asterisks, 



(Table 502) External view (No. 2) 



- 503 - 




(Fig. 503) External view (No. 3) 



- 504 - 




CFig.504) External view (No. 4) 



- 505 - 



Parts nxamber of the FDD 



.Name plate 



T 



O 





FO-55 j 













(Fig- 505) External view (No- 5) 



- 506 - 



5-2. MECHANICAL BREAK-DOWN AND PARTS LIST 



5-2- 


1. FDD (Refer 


to Fig. 506) 


Nos . 


Parts Nos. 


Parts name 


Q'ty 


Description 


1 


16152803-00 


Frame Ass ' y 


1 




2 


16802602-00 


Cord guide 


1 




3 


16787121-^00 


Sheet 


1 




4 


16802437-00 


Stopper, TOO 


1 




5 


14733730-00 


DD motor Ass'y 


*1 


FD-55{L) A '^' F, Note 3 


14733730-10 


DD motor Ass 'y 


FD-55{L) A,B 


14733730-50 


DD motor Ass 'y 


FD-55(L) G 


6 


16786981-00 


Spacer, IC 


1 




7 


17966790-01 


Set arm sub Ass'y 


*1 


FD-55(L) A,E 


17966790-01 


Set arm sub Ass'y 


FD-55(L) B,F,G 


8 


16786984-00 


Felt pad 


1 




9A 


16786984-00 


Felt pad 


1 




95 


1 C^ion r\-j c r\ "> 

■ — fvy»ij-V/^ 


Disk pad 2.5t 


i 


Note 4,FD-55(L)A,E 


10 


17966793-00 


Collet Ass 'y 


1 




11 


16385123-00 


Spring, pressure 


1 




12 


16802440-00 


Plate 


1 




13 


16786997-00 


Pad, disk 


1 




14 


16802550-00 


Shift lever 


*1 


Note 6 


16802592-00 


Shift lever 


FD-55(L) B,F,G:CSS 


15 


16802651-00 


Cable clamper B 


1 




16 


17966806-'00 


Head protector Ass'y 


1 


Note 5 


17 


16792288-00 


Holder 


1 




18 


16786990-00 


Cushion, holder 


1 




19 


17966801-00 


Lever shaft Ass'y 


1 


Note 7 


20 


17966802-00 


Clamp arm Ass'y 


1 




21 


16389017-00 


Spring, lever 


1 




22 


17966805-00 


TOO sensor Ass'y 


1 




23 


17966859-01 


Head load solenoid Ass'y 


1 


Note 8 



(Table 502) Parts list of the FDD (1/2) 

- 507 - 



Nos . 


Parts Nos . 


Parts name | Q ' ty 


Description 


'^ A 


•\-^r\/'/'r\Ar\ r\ 
i / :3 00:?'4*J— 


Hecid cdxricige Ass ' y 


" X 


FD-55(L) A, Note 9 


17966941-00 


Head carriage Ass'y 


FD-55(L) B,Note 9 


17966942-00 j Head carriage Ass'y 


FD-55(L) E,Note 9 


17966944-00 


Head carriage Ass'y 


FD-55(L) F,Note 9 


17966943-00 


Head carriage Ass'y 


FD-55(L) G,Note 9 


25 


16392009-00 | Spring guide A 


1 




26 


16392010-00 j Spring guide B 


1 




27 


14769070-00 | 


Stepping motor Ass'y 


*1 


FD-55(L) A 'V G, Note 3 


14769070-50 


Stepping motor Ass'y 


FD-55(L) A,B 


28 


16792265-00 


Steel belt A 


1 




29 


16392008-00 


Spring, belt 


1 




30 


16496492-00 


Washer, plate 


1 i 


31 


16802434-00 


Cable guide 


1 




32 


16766580-00 


Cable holder 


1 




33 


13189135 


Terminal (Faston) 


1 




34 


15532001-XX 


PC3A MFD control trB 


1 


Note 10 


35 


15531990-XX 


PCBA front OPT 


1 


Note 10 


36 


17966807-50 


Front bezel Ass'y 


1 


Note 11 


37 ! 17966808-50 
1 


^T'^^nt lever Ass ' v 


1 j Note 11 


38 


16389024-00 


Arm spring 


1 


FD-55CL) B,F,G 


39 


17966900-00 


CSS Ass'y 


1 


Note 8 









(Table 502) Parts list of the FDD (2/2) 



- 508 - 



Notes: 1. As to the parts with an asterisk in the Q'ty column, select 
appropriate one for the model, 

2. As to the parts with model name of FD-55(L) in the Description column, 
the parts is used only for the model, 

3. For the DD motor Ass'y of FD-55CL) A or B, either of 14733730-00 and 
-10 may be used. (Mainly -10 is used at shipment) . 

For the stepping motor Ass'y of FD-55 (L) A or B, either of 14769070-00 
and -50 may be used. {Mainly -50 is used at shipment) . 

4. Pad 9B is attached for the adjustment of head touch (refer to item 
4-4-9) and some models might not have it. Usually, double sided 
FDDs have not 9B pad, 

5. The head protector Ass'y applies only to the double sided models with 
head load solenoid. 

6. The shift lever (P/N 16802550-00) is used in all the models except 
for CSS models. P/N 16802592-00 is used only in the double sided 
CSS models. 

7. The parts number of the lever shaft Ass'y listed in the table is- the 

w wv^iiv^oij-vj. j.v,A±s^ . — i^KjiiajL icvcX aiicijL U i-isjia y wiixCli xti^iigCii iS uXj.JLexexiC 

should be designated with other parts number. 

8. The head load solenoid Ass'y applies only to the models with head 
load solenoid. The CSS Ass'y applies only to the double sided models 
without head load solenoid. The head load solenoid Ass'y and the 
CSS Ass'y will never be used together in a model. 

9. The head carriage Ass'y is supplied in combination with two guide 
shafts. Be sure to replace the head carriage Ass'y with these guide 
shafts. 

10. The parts number versions of the PCBA MFD control #B and the PCBA 
front OPT vary depending on each model. Refer to the name plate 
of the actual PCBA mounted to designate the version. 

11. The parts numbers of the front bezel Ass'y and the front lever Ass'y 
are those of FD-55 (L) standard color, black. For designating the 
other color, refer to the following table. Optional designation of 
colors than in the table or other forms, different parts numbers 
should be used. 



- 509 - 



Color 


Front bezel Ass'y 


Front lever Ass ' y 


Beige 


X / :7000U / 


X / r^ooouo— 


Gray G4 


17966807-53 


17966808-53 


Gray G12 


17966807-55 


17966808-55 



- 510 - 




- 511 - 



5-2-2. Screw, Washer 



Nos . 


Parts Nos. 


Parts name 


Description 


SI 


16400304 


Screw , pan , 3x4 , S , ZMC 




S2 


16400304 


Screw , pan , 3x4 , S , ZMC 




S3 


16470305 


Screw , pan , sems , 3x5 , S , ZMC 




S4 


16470306 


Screw , pan , sems , 3x6 , S , ZMC 




S5 


16470308 


Screw , pan , sems , 3x8 , S , ZMC 




S6 


16498579 


Screw, pan, three pieces, 3x6, S, ZMC 




S7 


16498580 


Screw, pan, three pieces, 3x8, S, ZMC 




S8 


16498712 


Screw, pan, three pieces, 3x8 




S9 


16400304 


Screw , pan , 3x4 , S , ZMC 




SIO 


16498296 


Color screw, 3x6 


Plastic screw 


Sll 


16420005 


Screw , flat , 2 . 6x5 , S , ZMC 




S12 


16420308 


Screw, flat , 3x8 , S , ZMC 




S13 


16498260-00 


Setscrew,3x3 




S14 


16351140 


E-ring, 3J 




S15 


16351160 


E-ring,4J 




S16 


16496062-00 


Mylar washer, 0. 3 5Tx4. 1x8 




S17 


16496060-00 


Mylar washer, 0.lTx4. 1x8 


For adjustment 


S18 


16496061-00 


Mylar washer , 0. 2Tx4 .1x8 


For adjustment 


S19 


16496005 


Flat washer ,5x12x0.8 




520 


16498711 






S21 


16420305 


Screw , pan , 3x5 , S , ZMC 





(Fig. 503) Parts list of screw & washer 



- 512 - 



5-3. PCBA PARTS LIST 

Following shows all the parts mounted on the PCBAs of FD-55(L) series. 

Notes for Tables 504 and 505: 

1. Parts with an asterisk are different depending on the PCBA 
versions. Select either of them. 

2. Parts with a double asterisks are not used in some PCBA versions. 

3. Parts with a triple asterisks are different in quantity and 
location depending on the PCBA versions. 

4. Refer to the schematic diagram of the PCBA as to the details of 
the parts with asterisks, 

5. Name plate version is different depending on the PCBA version 
used. 



513 - 



5-3-1. PCBA MFD control #B (P/N 15532001-XX) 



Parts Nos. 


Parts name, rating 


Location 


13441922-00 


LSI TEAC 1922-00 




U6 


13447358-00 


LSI TEAC 7358-00 




*U9 


13447358-01 


LSI TEAC 7358-01 




13441123 


TTL IC 7438 




U4 , U7 


13441235 


TTL IC 74LS04 




U3 


13441510 


TTL IC 74LS14 




Ul 


13441515 


TTL IC 74LS08 




U2 


13441245 


TTL IC 74LS74A 




U5,**U10 


13428129 


Transistor array, M54534P 


U8 


13423122 


Transistor, 2SB 810 H/F-F 




Q3,Q4 


or 13421211 


or 2SA 881 Q,R 






13424279 


Transistor, 2SC 2785 F-F 




Q1,Q2 


or 13424286 


or 2SC 2021 R 






1341378 


Diode, pair MA154WA 




CRAl , CRA3'vCRA5 , **CRA2 
**CRA6 


13411398 


Diode, pair lSS233-F,or MC921 




CRA7 , CRA8 


13411243 


Diode, 1S954 




CRl , CR3 


or 13411407 


1 or 1SS92 








Diode , zener , HZ7A2 




CR2 









(Table 504) PCBA MFD control parts list (1/6) 



- 514 - 



Parts Nos. 


Parts name, rating 


Location 


13497297 


i o Ju o I— \J JL 


ndt-TJOT-lr "7 "7 "7 "5 "3 no T 

iieuwoiA., /— / / — JJuii,J 


] *RA1 






13497296 


Resistor 


nptwrTrV 7—1 TfO T 








13497227-00 




array, l- /zz / , /-12P, j 


RA8 






13497228-00 


Resistor 


array , T-7228 , 7-lOP , G 


RA9 






13497229-00 


Resistor 


array, T-7229 , 7-lOP, j 


RA7 






13497255-00 


Resistor 


array , T-72 55 , 3 -6P , J 


RA5 






13497280 


Resistor 


array, SA 7-47Kn,J 


RA2 






13497269 


Resistor 


array, SA 6-4. 7f^, J 


RA3 






13497278 


Resistor 


array, SA 5-47Kn,J 


RA4 






13497287 


Resistor 


array, SC 4-2.2KJ^,J 


RA6 






11982479 


Resistor ,RN, 1/4W, 768Q,F 


*R17 






11982497 


Resistor, 


RN,l/4W,1.24Kft,F 








11982508 


Resistor, 


RN,l/4W,1.69Kfl,F 








11050121 


Resistor, RN,lW,120f2, J 


*R20 






11050151 


Resistor, RN,1W,150(^, J 








11050241 


Resistor, 


RN,lW,240fi, J 








11185104 


Resistor ,RD,l/4W,100Kn, J 


RIO 


11186331 


Resistor , RD, 1/5W, 330Q , J 


" *R13 






11186471 


Resistor, 


RD,1/5W,470J^,J 








11186100 


Resistor, 


RD,l/5W,10fl,J 


**R14 




R16 


11186473 


Resistor, 


RD,l/5W,47Kfi ,J 


**R18 




R19 


11186102 


Resistor , RD, 1/5W, IKft , J 


**R11 


'\, 


R12 



(Table 504) PCBA MFD control parts list- (2/6) 



- 515 - 



Parts Nos. 



11186222 
11186332 
11186362 
11186472 
11186682 



Parts name, rating 



Resistor, RD,1/5W, 2, 2Ki^, J 
Resistor , RD, 1/5W, 3 . 3KS^ , J 
Resistor , RD, 1/5W, 3 .6Kn , J 
Resistor, RD,1/5W, 4, 7Kfl, J 
Resistor, RD,1/5W, 6. 8Kfl, J 



Location 



'R21 



R22 



13256653 



Trimmer , 1/2W , 2 OKfl , M 



^R5 



12903065 
12903069 
12903220 
12903070 
12903071 



Capacitor , CE , lOV , lOOyF , M 
Capacitor, CE, 25V, 10pF,M 
Capacitor , CS , 16V, 33yF , K 
Capacitor , CE , 25V, 22yF ,M 
Capacitor , CE , 2 5V, 47y F , M 



C2 

*C12 'V' C15 

C3 
C33 



12902551 



12902553 



Capacitor , CS , 16V, 2 . 2viF , M 



Capacitor , CS , 16V, 4 . 7yF , M 



C17 



^C35 



*C6 

*,**C7 



12557334 
12557474 



Capacitor , CS , 3 5V , . 3 3y F , M 
Capacitor , CS , 35V, . 47yF , M 



CI 6 
C8 



12453152 
12453561 
12453561 
12453222 
12453332 



Capacitor, CQ, 50V, 0. 0015yF,G 
Capacitor , CQ , 50V, 560PF , G 
Capacitor , CQ , 5 OV , 560PF , G 
Capacitor, CQ, 50V, 0.0022yF,G 
Capacitor , CQ , 50V , . 0033yF , G 



^C20 



^C28 



(Table 504) PCBA MFD control parts list (3/6) 



- 516 - 



Parts Nos. 


Parts name, rating 


Location 


12454101 
12902599 
12902578 
12901228 
12902579 
12902588 


Capacitor, CQ, 100V,100PF,G 
Capacitor , CC , 5 OV , CH , 2 7PF , G 
Capacitor, CC, 50V, CH,22PF, J 
Capacitor , CC, 50V, CH , 8PF, J 
Capacitor , CC , 50V , CH , 2 4PF , J 
Capacitor , CC , 50V, CH , 56PF , J 


1*C23 
C18 
*C24 


12900771 


Capac i tor , CC , 5 OV , SL , 18 OPF , J 


C10,C11 


12902983 
12901417 
12901418 
12901421 
12901421 
12901417 


Capacitor,CC,50V,YA,470PF, J 
Capac i tor , CC , 5 V , YB , 1 00 OPF , K 
Capacitor , CC , 50V, YB , 12 OOPF , K 
Capacitor , CC , 5 OV, YB , 22 OOPF , K 
Capacitor, CC, 50V, YB, 22 OOPF, K 
Capacitor,CC,50V,YB,1000PF,K 


*C27 
*C31 

*,** C29 % C30 




Capac JL tor , CC , 2 5V , YF , . 02 2y F , Z 

Capacitor, CC, 25V, YU,0.1yF,M 
Capacitor , CC , 500V, YE , . OlyF , Z 


C4 , C5 , C9 , Cly , C21 , C22 , 
C32 

C25,C26 
CI 


12903080 
12902530 


14723570 
14723572 
14723572 
14723571 
14723569 


Coil, chalk, 120yH, J 
Coil , chalk , 330yH , J 
Coil, chalk, 330pH, J 
Coil , chalk , 150ijH , J 
Coil , chalk , 39yH , K 


■ *L1 
*L2 % L3 
L4,L5 









(Table 504) PCBA MFD control parts list (4/6) 



- 517 - 



Parts Nos. 


Parts name, rating 


Location 


13295084-00 


Ceramic oscillator ,KBR-480B4 


Yl 


13299164 


Socket, IC,14P 


J3(for RAl) 


13121109 
16322368 


Connector, 4P (172349-1) 
Connector, clamp, (172296-1) 


J2 

For J2 installation 


13121298 
13121155 
13121234 
13121235 
13121296 
13121297 


Connector , W6P , #80 , polarizing 
Connector, W6P, #7 5, polarizing 
Connector , S6P, #37 , polarizing 
Connector, W12P, #74, polarizing 
Connector ,S6P, #39, polarizing 
Connector, S8P, #39, polarizing 


**J12 
J4 

1 *'^^ 
1 *J5 


13121191 
13121189 
13121299 


Connector, 6P, {S6B-XH) 
Connector , 4P , (S4B-XH) 
Connector, 2P, (B3B-EH) 


J6 
J7 

**J11 


13121358 
13121359 
13121361 
13121363 
13121332 
13121333 


Connector , S2P 
Connector , S3P 
Connector , S5P 
Connector, S7P 
Connector , W14P 
Connector , W16P 


PM strap 

**DC1 4 straps 

TP7 'X' 10, G 

TPl 6,G 

HS 'Vi MX straps 

UR RE straps 









(Table 504) PCBA MFD control parts lisf (5/6) 



- 518 - 



Parts Nos. 


Parts name, rating 


Location 


13121149 


Short bar 


HS -v MX, UR % RE, 
PM, DCl 'v. 4 straps 


13000040 
16271169-XX 


Name plate 


***S1 'V' S18 
Note 5 









(Table 504) PCBA MFD control parts list (6/6) 

- 519 - 



5-3-2, PCBA Front OPT (P/N 15531990-XX) 



Parts Nos. 1 Parts name, rating 


Location 


17966812-00 1 
17966906-00 ' 


FPT sensor sub Ass'y 
Index sensor B sub Ass'y 


PQ51 
PQ52 


13423122 

13411243 
13413020 


Transistor, 2SB510 H/F-F 

Diode , 1S954 
Diode,lS953 


**Q51 

**CR52 
**CR51 


13419160 
13419161 
13121236 


LED,GL-5HD5 
TT?n f^T— SNC56 

1 .r. 1 J , Lj1-i jliivjw 

Connector , S3P , #38 , polarizing 


*LEID51 


11185151 
11186222 


Resistor, RD,l/4W,150n, J 
Resistor, RD,1/5W, 2. 2Kfi, J 


**R51 R52 
**R53 R54 


12903080 


Capacitor ,CC, ^ov, iL-rU.xpr 


C52 


13121187 

13061335-00 
16362294 


Connector , 2P 

Harness OPT B Ass'y 
Cable tie 


**J13 

For fixing harness 


16271169-XX 


Name plate 


Note 5 









(Table 505) PCBA front OPT parts list 



- 520 - 



5 4. SCHEMATIC DIAGRAMS AND PARTS LOCATION 

Notes for SCHEMATIC DIAGRAMS 

1. Resistor (R) and resistor array (RA) values are in OHMs , 1/8W, ±5%(J), 
unless otherwise specified. 

2. capacitor (C) values are in Microfarads. 50V, t5%(j,, unless otherwise 
specified. 

3. Tolerance symbols for R, RA, and C are: 

F: ±1% G: ±2% J: ±5% K: ±10% M: ±20% Z: .80-20% 



521 - 



PCBA DD MOTOR ShIRVO, PARri5 LOCATION (lype S) 




- 522A - 



PC3A DD MOTOR SERVO, PARTS LOCATION (Type K) 




- 522B - 



PC3A DD MOTOR SERVO, PARTS LOCATION (Type G) 




- 522C - 



PCBA DD MOTOR SERVO, PARTS LOCATION (Type T) 




- 522D' - 





R/03 
RI04 

fi- 



le 15 M 13 12 II 10 9 

MS 1720 P 
f j> I ^ f f l-tr 



ClOl 



0.056 









-ao. -to 


/5< F 


tIK 


-so 







Rill 
■2a K 

0.47 H^J^ 



O CONTROL 



|47 



K lOOO 
M 

Rioq 

— wv — 



Rloa 

— wv— 



I 2 3 4 5 6 7 8 Q 10 { / [2 



_VV^\ 

RII4 
3:50 + 



cm 

a.4.7 M 



/?//5 

330 

~Rn6 

330 



i n ~^ 

RII3 f?ll P fe 2-'^ ' 



^^,RII3 



300AH 



Wl 
33£ 



/?//7 ^7 



H3O0AH 



Clio - 

yLlOl 



cm 



33 



/?//8 

?.2 Af 



-0 + /2V 



/6V 



4. 

r-0 + 5V 



/20 



,RI0I 



VSRSfOM TABLE 



47 K 5./A1 



LED 
O GNO fOV) 



PCBA DD MOTOR SERVO, SCHEMATIC (Type S) 



^2Ar M 0.2W 





Cf66 <=f<=>1 
?v 0.4-7 Af 3SV 



4..7K /oak\4- 



UfOf HSt970L 



Ftr22 
■27ok 



■I'ZV 





UfOi 



ma h 



Rt2i> 
0.^9 i^w 



XR/2Q 
0.<f7fi 



I A Rr2, 



/8/rU 22Af 



-CZJ 



CD 



-O COAfTRQL 



9 e 



u/oz 



£3 



6 7 



AT 



R"9 3-2.2 



Z S JK 3 C 




\W2 IW( 



3-H3oQa 



PCDA DD MOTOR SERVO, SCHEMATIC (Type K) 



QlOl 

-o 




Rir 



Rn6 

/Sf< 



C109 



CRIO 



HZ5C 
SI Si S.I 



/o 



lit. 



0.022M R] 10 



1 



Clio 



0.022M 
2SV 



1 1 
O. 22 Af 



RIlS 

82/f 



U102 



IQI 



YIO^ 

5.53 ^ 



14 
i3f» a: 



IX 



"2 



O.OOfM 
2SV 



C112 

J3P /C 



R111 



CI02 

Ml- 



Rn2 

M /6V 



0,00/ -M 



25 V 

R1C6 

(OK" 



C106 

0.0/ M 



R114 




Rl04,o 




THS/03A 

E02 



V (c^: 



E03 



E01 

77/S /03/4 



R102 
4ro 



t|2V 
— ffi/ 



C101 



R102 

LEO 10 
f/0 3 f 

LEDI02(5 h 




■I-5V 



.LSD 
OV 



CONTROL 



PACE DD MOTOR SERVO, SCHEMATIC (Type G) 



en 

ISJ 

D 



•#-/2V(> 



COAJTffOL 




PCBA DD MOTOR SERVO, SCHEMATIC (Type T) 



PCBA MfD CONTROL #B , PARTS LOCATION 
(PCB ISSUE A G) 



DC] 0C4 




(Dip side) 



- 524A - 



PCBA MFD CONTROL #B, PARTS LOCATION 
(PCB ISSUE H ) 



REVISION 
VERSION 




PCB ISSUE 
(Dip side) 



- 524B - 



PCBA FRONT OPT, PARTS LOCATION 




R5l TI 




^ 525 - 















o 
















i 



















J 1 






2 




/A/ USE / MBAD LOAO 


4. 




OniYB SELECT 3 
IHOex /SECTQP 


(, 
g 




OKive SELBCT a 


tQ 




OK/vE SBLtCT 1 


'2 




HR/VE SELECTS 


/4. 






/6 




O/HECTIOAJ SELECT 


'8 




STEP 


20 




ivPITS &ATA 


72 




WHITS &ATE. 


21- 




TRACK S& 


2(, 




WRITE PROTECT 


28 




KEAO OATA 


30 




SlOE a</£ SELECT 


32 




/lEAOY 


34 




Sl&^AL G*JO 

(OOO A/OS. ) 


1 
% 

i3 



-wrO CONTROL. 

1 55:3700 1 -XX 



^I7V 

ov 
ov 



FRAME eitOUf^a 
CTASrOAJ TA&'i 

? 

r 



He AO CAfilfM6£ ASS'Y 



SIDE a 
HEAD 



SIO& I 
HEAO 



pca/K 

M^O COfTTROL 
'SS3200I -XX 



*JII 



1 


5V 




3 


INDEX SENSOR 




4. 


FOy^T LEO 




s 


FPT SE/^SOR 




e. 


QV 




7 


Jf DOD 





8 









J 3 * pee A 

\^ FHONT OPT 

I rSS3l990-xX 



* I/I FROATT 



INDEX Se/JSOR 



FHOMT LEO 



FPT SEAISOR 



■ PC8A VFO OPT 
CSOP C) 
/S532010-XX. 



*OO0K LOCK I 
SOLEMOID \ 
ASS 'T CSOP £■)! 



I if- BOOK CLOSE o c 
SWITCH — °- 
ASST CSOP Sy T*W( 



*■ AO SEMSOK ASS'r 

(SOP 01 



an. 



/son i 
w ~ 



HEAO LOAD I 
SOLBMOIO A%Sy\ 



TT^ACK SS 

SEAfSO/? ASS'Y 




3. Ooaff CLOSE smmzH ASS'Y: 

THsee /We 7TVO {/eks/o*js iu oook close swnnH /issor. crbfek to vchsion table-) 
Fon-oo, Pihi2 or :ru is cohuected to A/a/sMAc cLose tekm/ajal, or the. smtch, 

WHILE IT IS CONNECTED TO MCKMAL oPEM TERf^lnlAL FOK-OI. 

2. siOivALs nJiTH ooaece A%re.R/SK:s c^k) ake c»a/^<}eo /h some qptioajal. fbo 

VEHSfOfJS. f£T¥/l TO VEKSIOAl TABLE- U^UmE-o S/MAlS AKE /VOT cyfAV^O 
IfJ THAT VEKS/OA/. 
I. PARTS iVITH AaJ ASTBg/SK C*'> AKE USEE) /Xl SOME FOB VE/PS/OMS . 

REFEJi TO VERSION TABLE. UAIL/STeo PARTS ARE /UOT USED /*/ THAT VERSIOaJ. 




^' lQ4Q9gl8 



SZ6 



FDO VERSIOmS ■ 


MAIN SPEC 


X FWRTS 2 SI6MALS 


SIS-MALS 


A-OO.A-05 
E-02.B-H 


5 SIDE . ML SDL 


PCBA VO . HLS0L>^53T 




S-01. a-06. Ffll 
F-O5- 3-04 . P<?3 


D SIDE . HL SOL 


PCBA FO , HL SOL A5ST. S 1 HEAD 




E--2I 


S SIDE . CSS 


PCBA FO 




B-20.S-?«? 
F-22.&-23 


D SIDE . CSS 


PCBA FO. 51 HEAD 




A-12. j 


S SlOe . HL SOL. 
1/1 


PCBA FO. HL SOL ASST. 1/1 FB ASS-T 




B-t3. j 


D SIDE . HL SOL 
l/( 


PCBATO. HL SOL ASS'r. SI HEAD. 

1/1 FB ASS'Y. criQ 




f-iO j 


D SIDE . HL SOL 
ANR 


PCBA FO. HL SOL A5S*r. SI HEAD 




F-51 


D SIDE . CSS 
anR 


PCBA FO. 51 HtAD 




8-32, 


D SIDE . HL SOL. 
DL SOL 


pCBA FO CVKlTH J5 DOD^I-ZV)- ^'3- 
HL SOL ASST. 51 HEAD. DLSOLASST 




a-37. 

F-i8. ^-i? 


D SIDE , CSS. 
DL SOL 


KBA ro ^u"TH TS DOD-S, CZVJ. OTIS 
SIHEAD. DLSOLASST 




B-35 


P siDt. «L SOL 
DC 5W (-00) 


FCBA TO. HL SOL ASST. S1 HEAD. 
DC SW ASSTf-OO). Til 


1 i PI W 34- ^ 

DRIVE STATUS 


r-36 

F--"-! 


1 D SIDE . CS3. 
1 DC SW C-00) 


PCBA FO. SI HeAD . DC S*J A5S Y(-00) 
Tl( 


■3-/ PfW34- 

DRIV^; STATUS 


F-4.2 


j D SIDE. HL SOL 


PCBA F^O-. HL50L A-SST, 51 HEAD 


Xl PlW 6 ■ rgadv 


^.4.7 j S SIDE . HL SOL 
E-49 ! VFO MASTER 


PCBA VFO . HL -SOL ASST 


Tf PIN4: FM 

Tl PIN -2: WIMOOW 


r-50. 


j D SIDE . HL SOL 
j VFO MASTER 


PC8AV/FO. HL SOL ASST. 51 HEAD 


Tl P(M4- ■■ FM 

T( PIW2 : WIMDOW 


A-52 
E-54. 


2 S/OE. HL SOL 
(/FO SLAVE 


PCBA FO. HL SOL ASST 




3-53 

F-E5. a--56: 


D SIDE. HL SOL 
VFO SL4.VE 


PC3A Ffl . HL SOL ASS'Y 




E-5S 


S SIDE, CSS. ANRC 
OC SWC-OIJ 


> PCBA FO- DC SW ASS'r(-on 
XII 


Tl PIN2: DOOR CLOSED » 
Jl PIN 6 ' DOOR CLOSED 1 



























VERSION TABLE 



ABBR£VIATBD ^MEZ AKE AZ POCUXUS : 
3 S/DB : ^/DB O S/DE 

Hi. SOL -. HSA LOAD SOLE^OfD 

3( H&AD - S/OE I fi£AD 

OC S»i • Do°R Ci.oS£ SMTCJ-) 

HO HO sei^soR 

P<lBA Vro : PCBA '^FO apT 



DL J:ot. 
1/1 TB 
D ^£AJ 
PCBA T=ty 



DOUBLE. SfD£ 

DOOR LOClC SOLE/UOlO 

1/1 PKOfJ-T BE-ZEL (FVLL HiaHT^ 

Of SAT SE*jSaK 

PcBA 'FHOfJT OPT 





M « ; 










IH^i an*-* ^ s B ; >£ 










jam ^^^y^ 








MSI i ■ ■ • 


iH {j£ mm 





TEAC 7- -< T' -y -7 



FD'-55 



TOTAL. DI.A<jPAMa/^2 



^' 1040912 18 

527 I -2 5J 2 



"0? 

"O 



S1« 



SIDE I 
HEAD 





C4.. S. 9. 32 
.022Z 



CI .0/7 5001^ 



FAfTOfiJ 
FRAMB C 



->/2V 


12 V 




-t> OV 




J7-( 




12^1 








T7-2 


-t> 5V 


OV 








J7-3 






O 






J7-4. 




5V 


■0 — — O 



— O /?ESE/?veD 

'75-7 

— O dod\ 

'J5-8 SOP E 

~ /2V J 



/2V 
OV 

SPIMDLE MOTOR 



Rio iOOK I/4.W 



7 5-/<^^^iS 1V^« £«080E Asr^^,^<S c^) tf5£a ^« CHA*J6£0 /A/ S-<>M£ d^/^^-A^ TOO 

VEet/0^:S. REFSR TO FD'SS TOTAL OlA&RAf^ /,A/D /T'S VEeSIOAJ TABLE 

6 paiAPI2IHA KEY PQS/T/Q^S FOR COfVNECTOR (J) ARE : 

J, :'bET^£EM P,M^ AMO 6 T^: JS: P'^2 J-f ■- P'A/<5 J/2 : / 

5. ;?fFt/7 TO SWO/?TB/»/? 5£ifC7VOAJ TA0i£ <MS^MX. UR - RE . P>^ ) AS 70 THE S,PP>M4 
POSmOHS /VJO THEIR FUNCTIONS. 

a. TOLERANCE SYMBOLS FOR R . RA . AND C ARE : 

dr=2::zy. J--2:5% K-.itov, m : ±70'/. Z 



3. CAPf^arOR (CI VALUES APS 
SPFCIFIEO. 



Tgo- 

IN MICROFARADS, 50\/ OR HI6HER , ± 



20% 
5% CJJ , 



U.VLESS OTHERWISE 



RESISTOR (R) AA^D RESISTOR APRAY(RA) VALUES ARE />J OHMS. 1/8 OR dREATER . ±SV, fT), 
UKJUBSS OTHERWISE SPECIF/EO. 

PARTS WFTHAN ASTERISK C^) /^R£ DIFFER6/JT EACH PC3A VERSION. 

REFtR TO VeRS/ON TABLE. UNLISTED PARTS ARE ^JOT USED /-V THAT VERSION. 



10010220-00 



pCBA J f^l^ 
uf:e^lOAI3l\ SPEC. 


^ PARTS 


- oo 


S. Side 
A STD. 


Q4. CFI HAt(^201 . Ki3(33O).RIA.<l0).Rt7(U24.K1. R2Qll20^.R2t(2.2K) . RZ(20IC) 
C6C4..7}. C70 CISQOP). C23(l00Pi.C74.(S&p-) . C27 ( lOOOPi . C2S (220aP) . C3I C2ZaOP1 
LI ~L3 (330jiM) . U9 


-01 


-18 tpi 
£>. Sld:e 
a STD 


04 CRI CRA2 CRA&.liAU330^.Ri3<330-I.RI4.a01.RI7ll.24.K).R2oa20). R2t(2.2K:) 
C(>~C7'.4~7). C20(ISQ0P->.C23(I00P). C24./S6P). C27(IOaoP). C28 (7200P}. CilC220OP1 
Lf L3 (3^0 juN) . RS CZOK) . C73S3-00) 


-02 


96tLpL 
5. Side 
F STD 


04. cm. RAI(3301 Rl3(330t.Rt6llO).PlTa.e,9K),R20(2'W>. R2I C<k7K ) . RS C70K) 
C6W.7). C20(I500P). C23C100P-). C24.(56P]. C27(I00QP^. C28 (7200P1. C3ia200P) 
LI~L3 C330,uH^. U9 (T368-OOy 


-03 


96-cpC 
O. Side 
F STD 


roi roi-y roa.^ CA/f^^n) RI3(3H0) R16(I0) RI7CI.6.9K) . R20(2'Ui'). R2f C^7K) 
Cb~C7C4-n-). C20(l50OP1. C23UOOP-I. C24.(S6P1. C27(IOOOP). C2SC2200P). C3I C220OP) 
Lt~L3 OSOuH). esr20k-). U9(73Sr8-00^ 


-04- 


96 tpi 
O. SldS 
G- STO. 


Q-a. CRt CPA2 CRAe.. ltAIC3301. RI3<3301. RlS(IO). Rlb(IO). PIT CTASI Rie-RI9(4.7K) 
r,-:^,,rn\ =4-1 iprr'^nic} Cf,~C7(2.?) C20(5bOP) C23C27P) C2t(2'a-P). C27(4-70P) 
ClQC^hon C29-C30C220CP^. C3tCfZOQP>. Li 0^20 ^H-^. Li < /SOm^"^ ^ U<7C73Sa'-Ol) 


-OS 


49 tpi. 
S Sids 
NUA 


THB OTHEffS ARE THE SAM^ AS ~ 00 . 


-06 


aSxpi 
O.Side 
iVEB 


RAiCtK-). /?r2(tK). /S/3(^70). 

THE OTHERS ARE THE SAMB AS -Of. 


-OT 


F. AUR 


y.r^ ffe rruAxi/^r^ -m ) THE OTHERS AR£ THE SAH^ AS -03, 


-03 


&. OL 


-f*. y yi^A ttje,r TV^ QO 1 TUC /TTT/PjPT 'FH£ S^A^f AS —Of. 

JSCCnAn/CTc. or^-'. trie, t-^ » Tcr/c o >-»/tc ■ •- 


-ai . 


F. OL 


T*\(CHA^6i: TO BP) THE QTHB/3Z ARE THE. SAME A5-OB. 


- to 


0-. DL 


-rt!- f y, lA. r- ~r-f\ a t> ^ TUF CTTNT^P^ ARE THE SAME <A3 — 04- . 


- n 


B. OC 


Jll : 55 CUT, S6 JUMPER , UIQ , RIICIK) . C2S C^7 M I6V) . STRAP POST OCI~^ 
THE OTHERS ARE THE SAf^E AS -Of. S7 CUT 


-12 


F. OC 


J-n. SS CUT. 54, UOMPER. UIO. RUOKI. C35 C^.7 M leV) . STPAP POST DCI~4- 
77m OTHERS ARE THE SAME AS ~03. S7 CUT 


-13 


F. ROY6 


S4- TUHPER THe OTHERS ARE THE SAME AS -03. 


-M 


A ■ VfO 
mastsa 


SIJUMPEP; C2t(SP) Jr2(6P). THE OTHERS ARE THB SAfAE A\-, -00. 


-IS 


B. VFO 
/■•lASTEh 


'^(lUMPER C-za-CSP). a-l2(&P). THE (OTHERS ARE THE SAME A:^-Of. 


- I& 


E. VFO 
MASTER 


SITUMPER. C24.ceP). J^l? (6P). THE OTHERS ARE THE SA^ME A'a-O^. 


- 17 


F- VFO 
MASTSI' 


S17UMPER. C2.4.(BP). J-/2 (6P). ThE OTHERS A/!E THE SAME /15 -<33 . 


-18 


&. VFO 
MASTih 


S,( JUMPER C-^(dP). J-r2(6P}. THE OTHERS ARE THE SAME Ai,-04. 


- 19 




RAICIKl Rl2CtK^. RI3(^70}. CZ8C33aaP). C29CrOOOP) . C30CI000P) 
THE OTHERS ARE THE SAME AZ -03 . 



VBRSIOfJ TAatE 



P/N 1 5532001 -XX 

















TEAC T--<-l"j'7 *fe*^4± 




























ro -- 55 














PCBA MrO CONTROL 

5» B 






* H a 














\83-rZ-26 






SCHEMATIC 2/^ 












' «' 


IS] • 


id4lO^Sjll8^0i \ 

S29 1 2 H 3 


SilQl I I ■ - 


m iS. mm 



o 

--•^ 

CI 

-o 

■CO 



9 If 



PCS A. || /aaUj 1 ~~ ~ — 

VCKS/ONZi SPSC. \ ^ m?75 


- ?o 


11 A. JMffj C24.eeP} . THE 0T»EP5 AKE THE SA/^E AZ -OO . 


- ^r 


|| a. ZLAVE \ C24. (3P) , THE OmcKS A/?E THE AZ -Ol . 


- 72 


1 E. SCA{/E CM rep). THE OTHEPS AKE THE S4/W£r -02. 


- 22 


1 F. ziAve 


C-Za. (SP). THE OTf^EPS AflE THE SAME AS -a3. 


- 24- 


j| 6-. SLAVE 


C24. C8P). rWf OTHERS AflE THE SAMS AS-oa. 


- 25 


1 E. M/C 


Jtt. S7CUr. SS (STKAP POST) . S 2 (STRAP POST). RiHIIC}. RI7 CI-SOlC) 
a^'^as (CHAMtfE TO 33 «■ 16Vi . 
THE omeRS AKE THe SAME AS-02. 









l/£--?S/OAy TABLE C COATriAIOeO i 



P/M /5532a0f-XX 



! j ■ • i j 






TEAC ^-cr -jo t*s:*4± 


i i • • 1 1 


! ! • • 1 ! 


tk±. 






FD-S5 


i i • • 1 \ 




a« 


PGBA MIFD COMTKOL 


7f.tM 












mm 








SCHEMATIC 3/, 


tttt 




93- i -23] 






•^s-e _ ( H) 




104091180 i 






Ml ffi ma 





o 

CO 

ci 
o 

CO 



INDEX SENSOR 



TLOffT LSQ 
FPT 5EMS0R 



o- 



o- 

JS-6 
O- 



o- 



O— 



■^■Si' reuov/ 



*RS2 /SO '/HM^ 



*RSt '50 



csr j*= 

• /OOOP K 



JIO-I 

— O 

J/O-2 



T/3-2 

— <^ 1 
j-,3_, SOP £ ^f* 

— O > 



S. S/<}/uhL3 v/ITti BOUBLS ASTBK/5K5 C'f'if^ Afi£ 0S£0 SOME OPTIOfjAL J^OD 
\/E/<sioAJS. REPBR TO rOSS TOTAL OM<?/e/iH MO ITS VSRSIOfJ TABLE. 

POLAklZINe KEY POSmoU POR C<MIN€C-rOf> /S f2 . 

3. CAP^t/TOX CO t/ALUES ARE /H AA ICROFARADS , 50V OR HIQHER , tSV-CT). U/^OSSS 

QTNEAyV/SE ^PECjriED. 
7: RES'S-TOR (R) VALUES ARE /H OM^S . I/BW OR GREATER, i £•/; CT) . CJ/^LESS CTTHBRWIZE 

SPECf~/£-£>. 

A/OTES f. RARTS HITH Aai ASTERfSK CX-) ARE DIEFERE^JT /N EACH PCBA x/eRSro/il . 

RSFE/^ TO VERSIOfJ TABLE. UHLISTSU FIARTS ARE MT USEE) /A/ T/fAT \/£RS/ON. 



10O1023(h0O 



PCSA 
VERS/O/^S 


MAW ypec 


*■ PARTS 


-OO 




LEG CI CREH-) . RSI. CS2. as CSP) 


-01 


SREE^J LEO 


LE£> &/ (6REE>^) . 1^51. CS2. . (SR} 


-02 


//; SIZE 


RSI. CS2. JS-CS-P). ytO 


-03 j OOOR LOCK 


L£C5I(RED). a SI. CRSt . ■ CRS2. RS2 . RS3 . R5<- 
C52. J'3 . J-S <C'/AA/dE TO SP) 



P/N 15531990 -XX 



TEAC ^-c-F-y ^tt^**t 



FD - 55 



a« PCBA' FRONT OPT 



SCHEMATIC 



fs-E ( ») 



104iQi9^ilj9 



I it 



TEAC Corporation of America 
7733 Telegraph Rd., Montebello, CA 90640 
[213] 726-0303