Panasonic JU-475-4 User manual

Service
Manual
Flexible Disk Storage Drive
JU-475-4
Panasonic

so
10.
11.
12.
13.
14.
15.
16.
17.
18.
CONTENTS
PARTI Page
INTRODUCTION: z; a A A A eee a a 1
MODELS AND MODEL NUMBERS .................................neneneneenaeetensusesusneee nen iGO 1
2.1 5:25inch FOD SONOS ze a b b o td Hud 1
SPECIAL TOOLS u isba can eos dE ij Wi E GTE SIS mäele W a A 1
OUTLINE OF MAINTENANCE ........................................................................ 2
44 AligamentDiskette: issir Idi mia Ta e bt okt 2
42 Exerciser > pcs tute se a L A a ti us 2
DIAGNOSTIC PROCEDURES ......................................................................... 2
5. Error Symptom Recognition .........LL rr asa aN S 2
5.2 Soft Error Detection and Correction ........................................................ 2
5.3 Write: ETO, sortere di ia ame ae PRESSE ADE e EPO Da AD ia eat 2
5.4 Read Error ido A 3
5.5 A iD ia kt a ae tema ahh daa eddies Veke DEA 3
5.6 Interchangeability Error 22.26. ce cece r rr ran rnnnzrenzza 3
TROUBLE: ANALYSIS" assi sais Se pindadele ari dada ww vine bee Melb edie tee tee Waves a ede we weet eee E 3
6.1 Trouble Analysis Procedure... 2.2... ll corro 3
6.2 Troubleshooting Flow Chart ...... 2.22... rr eee e nn 4
6.3 Trouble Analysis Table ..........................:..0:ererereeeneenenneseeeeeraseeeera seene 5
PREVENTIVE MAINTENANCE ....................................................................... 6
SPECIFICATIONS: 4 assa ss a Sees GG em ama o arenaene köie A aa a 6
ADJUSTMENTS AND VERIFICATIONS ................................................................ 7
9.1 Motor Speed Verification (Index Period) .................................................... 7
9.2 Write Protect Verification Ruya uu lulus senennnnnennnzenenzznnnnnnzznrnnnnzenezznnzna 7
9.3 Head Output Verification GT Sel Ok Wack ae ean CENA oe deo nts A REESE 7
9.4 Output Modulation Verification ........................................................... 8
9.5 Resolution Verification .........................::::::ersrerreeenrresetatss nr 8
9.6 Radial Alignment Verification and Adjustment .............................................. 8
9.7 Azimuth Verification" curar tk lade seas para iD 9
9.8 Index Burst Verification and Adjustment _.................................................... 10
9.9 Track 0 Sensor Adjustment ................................................................ 10
9.10 Asymmetry Verification su S u g tau rr ih 11
TESTPOINTS sets diac oe Oy Po w san a we ees 12
PANASONIC ALIGNMENT DISKETTE ................................................................. 13
PARTII
REMOVALS AND INSTALLATIONS ................................................................... 14
12.1 PCB Removal and Installation .............................................................. 14
12.2 Front Plate and Handle Removal and Installation ............................................ 14
12.3 Track 0 Sensor Removal and Installation .................................................... 15
12.4 Collet Assembly Removal, Installation, and Adjustment ...................................... 15
12.5 Clamp Assembly Removal and Installation .................................................. 16
12.6 Write Protect Sensor Assembly and Index Sensor Assembly Removal and Installation ............ 16
12.7 Cartridge Guide Assembly Removal and Installation ......................................... 17
12.8 Stepper Motor Assembly Removal and Installation .......................................... 18
12.9 Head Carriage Assembly Removal and Installation .......................................... 18~ 19
12.10 Drive Motor Removal and Installation ......................................... SAY 20
12.11 LED Assembly Removal and Installation .................................................... 21
12.12 Lifter Unit Removal and Installation ..........00 Lane nee nnnn ene eee eees 21
12.13 Media Lifter Removal and Installation ...................................................... 22
12.14 Media Sensor Assembly Removal and Installation ............................................ 22
EXPLODED VIEW L: mis vedas Sue ekke malai EE sa A add 23
REPLAĊEMENT PARTS LIST: iii iii A s i sal 24
REPLACEMENT PARTS LIST FOR PCB ........................nnenuervenesenevasearsunneseeennne ave nn 25-26
SCHEMATIC DIAGRAM): sims O died Gnd DOP owy ed 27
CIRCUIT BOARD: hr ġa dead 28-29
BLOCK DIAGRAM) ii ao 30

PART. |
1.
2.1
3.
INTRODUCTION
This
service
manual
consists
of
two
parts,
Part
|
covers
maintenance
description,
adjustment
procedures,
and
trouble
analysis
and
Part
Il
covers
disassembly
and
reassembly
procedures,
parts
list, and
PCB
circuits.
Part
|
encompasses
maintenance
instructions
for
all
Floppy
Disk
Drive
(FDD)
models.
Refer
to
the
highlighted
applicable
items,
and
perform
maintenance
work
on
the
FDD.
Note: Thisservice manuals is prepared for maintenance of the FDD.
Do notuse this manual for judging pass or fail criteria in inspections.
MODELS AND MODEL NUMBERS
5.25inch FDD Series
48TPI JA-551
le JU-455
96TPI
JA-560
JA-561
JU-581
JU-585
SPECIAL TOOLS
The following special tools are used for FDD maintenance.
Table3-1 Special Tools
Tool 5.25 inch (48TPI)
JA-551/JU-455 | JA-561/JU-465
loscilloscope Somia | || | |||]
Probe(10:1) | po |
[Frequencycounter | [o
Note: *&: Stand for the same as left.

4.
4.1
4.2
5.2
5.3
OUTLINE OF MAINTENANCE
e The following tools are required for maintenance of an FDD.
Alignment Diskette
Alignment
diskette
is
used
for
head
actuator
alignment
and
index
sensor
adjustment.
Use the
right
diskette
as
shown
in
Table
8.1.
Exerciser
The
exerciser
enables
you
to
make
all
adjustments
and
inspections
necessary
for
an
FDD.
Its
functions
include
the following.
(1)
Seek
increment
or
alternate
tracks
(2)
Read (but
no
data
compare)
(3)
Write
1F
or
2F (All
'O'sor
"1"s)
(4)
Head load
(5.25inch
FDD
with
optional
head
loader)
(5)
Recalibration
to track
0
The
exerciser
has
switches
and
indicators
to
execute
a
specified
function.
DIAGNOSTIC PROCEDURES
Error Symptom Recognition
Errors
that
occur
because
of
the
wrong
operating
procedure,
wrong
programming,
the
use
of
a
defective
diskette,
or
soft
errors
due
to
external
causes,
such
as
contaminated
air
and
random
electrical
noise,
are
often
attributed
to
an
FDD
failure.
Unless
a
visual
inspection
of
the
FDD
reveals
an
evident
assembly
fault
or
a
defect,
always
confirm
errors
with
another
good
diskette,
and
another
known
good
FDD.
Soft Error Detection and Correction
Soft errors are normally caused by the following.
(1)
Contamination
between
read/write
heads
and
diskette.
This
kind
of
contamination
can
be
easily
eliminated
by
the
liner
in
the
diskette.
Please
follow
the
appropriate
procedures
provided
with
the
cleaning
diskette.
(2) Random electrical noise, normally a few microseconds or less.
(3)
Small
defects
in
written
data
and/or
track
not
detected
during
write
operation
may
cause
soft
errors
during
read.
(4)
Faulty
grounding
of
the
FDD
or
host
system
can
also
cause
soft
errors.
(5) Wrong motor speed is another cause of soft errors.
Take
the
following
steps
on
the
controller
side
to
recover
from
the
soft
errors
mentioned
:
above.
(1) Read the track again ten times or until the data is recovered.
(2)
if
step
(1)
above
fails
to
recover
the
data,
access
the
adjacent
track.
Then
return
the
head
to
the original
track.
(3) Repeat step (1).
(4)
Any
error
that
cannot
be
corrected
by
the
above
procedure
is
irrecoverable.
Write Error
if
an
error
occurs
during
write
operation,
it
is
usually
detected
during
the
next
revolution
by
performing
a
read
operation
called
write
check.
To
correct
an
error,
write
again
and
repeat
a
`
write
check
operation.
If
the
result
is
unsatisfactory
after
ten
or
more
write
operations,
perform
a
read
operation
on
another
track
to
determine
whether
it is
the
diskette
or
the
drive
that
is
wrong.
If an
error
persists,
replace
the
diskette
and
repeat
the above
procedure.
If
the
error
still
persists,
assume
the
FDD
defective.
If
the
error
is
corrected,
the
diskette
is
defective.
It
can
be
thrown
away.

5.4
5.5
5.6
6.1
Read Error
Most read errors are soft errors. Data can be recovered by following the recovery procedure in
section 5.2.
Seek Error
Seek errors are caused by the following.
(1) Stepper motor or stepper motor drive circuit is faulty.
(2) Faulty Carriage
There
are
two
ways
to
recover
from
a
seek
error.
One
is
to
recalibrate
to
track
0,
and
seek
back
to
the
original
track.
The
other
is
to
read
the
ID
field,
check
the
track
number
on
which
the head
is
located,
and
move
the
head
away
from
it. Read
it
again.
Interchangeability Error
Data
which
is
written
by
one
FDD
may
not
be
read
by
another.
This
error
is
called
a
interchangeability
error,
which
can
be
caused
mostly
by
the
following
reasons,
which
should
be
checked as
follows.
(1) Head misalignment: Refer to Adjustments and Confirmation section 9.6.
(2) Head output too low: Refer to Confirmation section 9.3.
(3) Motor speed difference: Refer to Adjustments and Confirmation section 9.1.
(4) Format incompatibility. |
TROUBLE ANALYSIS
To
determine
the
cause
of
trouble
whether
it
lies
in
the
FDD,
diskette,
or
controller,
replace
the
diskette
and
the
FDD
with
good
ones.
If
the
FDD
is
assumed
faultv
as
a
result,
follow
the
procedure
below.
|
|
5
Trouble Analysis Procedure
FDD trouble may occur in any of the following ten forms.
(1) Index detection failure
(2) 1/O 34pin signal failure (Disk Change / Ready / Media In / Media Out)
(3) Track O undetectable
(4) Noseek
(5) Nowrite
(6) Noread
(7) Readerror
(8) INUSE LED won't light.
(9) Write protect undetectable
(10) No head load (5.25inch FDD with optional head loader)
Check with the troubleshooting flowchart in section 6.2.
CAUTION:
Be
sure
to
switch
the
power
off
before
removing
an
FDD
or
PCB
from
the
operating
system.

6.2 Troubleshooting Flow Chart
Table6-1 Troubleshooting Flow Chart
Problem
Remains the Same after NO Diskette
Replacing
with
Good
Defective
Seek
NO
Diskette7 Operation
OK?
YES
YES
Problem z
Remains the YES Controller Write SW On
Same after Replacing Defective
with Good
FDD2
NO Write
Waveform NO
Run the operating svstem and er Pee
check. Record all diagnostic E
information on tracks and sectors
as far as the program permits.
YES
Write SW Off
install Exerciser on FDD
Power SW YES Read
Waveform
DCSW On on Oscilloscope
Drive Select SW OK?
Head load SW >
On
NO
Index
tame NO Check item 1, OK after BO
Flashes? Table 6-2 head cleaning?
YES YES
1/0 34pin NO Check Item 2 FDD online test
signal output Table6-2 `
OK?
YES Read YES
Error, CRC
Recal
SW
Error?
On
NO
FDD
Track 0 NO Check kem 3. IN USE LED NO
Lamp Lights at Table 6-2 Lights?
Track 0?
YES YES
(When Head Load option)
Write NO
Head Load
Operation OK?
NO Check Item 4,
Table 6-2
YES YES
Protect Lamp
Lights?
END
Check Item 5,
Table 6-2
Check Item 6,
Table 6-2
Check Item 7,
Table 6-2
Check Item 8,
Table 6-2
Check item 9,
Table 6-2
Check Item 10,
Table 6-2

6.3 Trouble Analysis Table
Table 6-2 Trouble Analysis
men] vm — [s] — — G —
Index detection failure | 1 |Colletpartfaulty
Drive motor control PCB
Drive motor fault
ndex LED faulty
ndex detector fault
ndex LED/index detector installation faulty
PCB motor on circuit
PCB index detection circuit
See Item 1.
PCB disk change / ready / Media in / Media out ciuciit
Track 0 assembly
PCB track 0 detection failure
See item 1.
See Item 2.
Head load solenoid
PCB head load circuit
Stepper motor
Guide shaft contamination or damaged
PCB stepper driver circuit
See Item 1.
See Item 4.
Head disconnected
Head shorted
Head load bail height wrong
PCB write circuit
See Item 1.
See Item 4.
See Item 6.
PCB read circuit
See Item 1.
See Item 4.
See Item 7.
Alignment
Azimuth
Index burst
Asymmetry
Limiter
Track 0
Head load time
Index period
PCB read circuit
LED part
PCB IN USE circuit
Write protect part
Write protect circuit
w
VO 34pin signal failure 1
Track 0 detection failure
No head loading
|
I Read error
— å | a
won't light
Write protect
failure
~

7. PREVENTIVE MAINTENANCE
No preventive maintenance is necessarv for anv FDD under normal conditions.
However if adjustments are necessarv, the procedures in this manual must be followed.
e Adjustments (Refer to Table 8-1)
(1) Make a read/write head radial adjustment at the specified track. (Sides 0, 1)
(2) Make an index burst adjustment at the specified track. (Sides 0, 1)
(3) Make an azimuth measurement at the specified track. (Sides 0, 1)
CAUTION
Do not write when using alignment diskette. Check that write protect sensor is properlv operating
with a data diskette.
Note: Section 9 describes the adjustment procedure in detail.
8. SPECIFICATIONS
Table 8-1 Specifications
MINI (a) type
Drive motor is dual speed type. (300 rom e 360 rpm)
Parameter
| 1 jindexperiod |
Output level
Resolution
| 4 |
Radial Alignment
| 6 [Azimuth |
a [rado |
| 9 [Asymmetry |
Head load time
MINI (B) type
Drive motor is fixed speed type. (360 rpm)
Parameter
| Í |Indexperiod |
Output level
Modulation
| 4 [Resolution |
Radial Alignment
| 6 {Azimuth |
Index burst
[fa
E
Head load time

9. ADJUSTMENTS AND VERIFICATIONS
9.1 Motor Speed Verification (Index Period)
(1) Insert a diskette, run the motor, and clamp. Refer to the index period column of Table 8-1.
(2) Step to the specified track.
(3) Connect a frequency counter to the INDEX signal: TP7
(4) Check that the freguency counter readings meet the specifications of Table 8-1.
9.2 Write Protect Verification
(1) Check that the exerciser's write protect lamp goes on and off as a diskette is inserted and
removed as specified in the table below.
Diskette with write protect Diskette with write protect
hole open hole closed
(Not write protected) (write protected)
9.3 Head Output Verification
Use a new diskette if possible to identify head failure for this check.
(1) Insert a good diskette.
(2) Runthe motor.
(3) Stepto the track specified in the output level column of Table 8-1.
(4) Connect the oscilloscope probe as specified below.
Invert channel 2 and select the Add mode.
Set vertical deflection to 10 mV/division and horizontal deflection to 20 ms/division.
(5) Write 2F (all "1"s) on the entire circumference.
(6) Check that the average output level meets the specifications of Table 8-1.
_ Vmax + Vmin
Vaverage =
If it does not meet the specifications, refer to Item 7 of the Trouble Analysis Table.

9.4 Output Modulation Verification
9.5
9.6
Modulation is calculated by the following formula.
max 7 Vmin
Modulation = Amae Vin x 100 (%)
Vmax + Vmin
Using the value obtained in section 9.3, and check that the calculated value meets the
specifications of Table 8.1.
Maximum voltage Value: Vmax
Average Voltage
Minimum Voltage Value: Vmax
Fig.9-1 Modulation
Resolution Verification
(1) Leavethe oscilloscope in the same condition as mentioned in section 9.3.
(2) Resolution is calculated by the following formula.
Resolution = V2raverage x 100 (%)
Vif average
(3) Check that the calculated value meets the specifications of Table 8-1.
Radial Alignment Verification and Adjustment
Introduction
This adjustment is normally not necessary.
If the mounting screws for the stepper motor loosen, or if parts become defective, or if a
compatibility error occurs, check and readjust according to the following procedure.
Steps(4) to (9) below should be performed regardless of the type, CE or DAD alignment diskette
used. Use an alignment diskette suitable to the type of FDD to be adjusted according to Table 3-1.
(1) Insert Panasonic alignment diskette.
CAUTION:
Be sure to leave the alignment diskette under room conditions for 20 minutes before
adjustment.
(2) Step to the track specified in the radial alignment column of Table 8-1.
(3) Leavethe oscilloscope in the same condition as mentioned in section 9.3.
e CatsEye System
(4) Check the output waveforms for sides 0 and 1. They should appear as in Fig. 9-2.
(5) The two waveforms should appear in the amplitude ratio in the radial alignment column of
Table 8-1 or better.
(6) I the specified ratio is not satisfied, loosen the two mounting screws for the stepper motor.

(7)
Move
the
stepper
motor
along
the
base
bv
hand
until
the
two
waveforms
assume
approximatelv
the
same
amplitude,
and
retighten
the
mounting
screws.
(See
Fig.
9-2.)
(8)
Step
the
head
outward
(track
0)
and
inward
(track
79),
and
confirm
that
the
adjustment
has
been
completed.
(9)
After
the
radial
adjustment,
be
sure
to
confirm
track
0
sensor
adjustment
as
described
in
section
9-9.
Note:
Alignments
on
sides
0
and
1
are
adjusted
at
the
factory.
If
they
are
misaligned,
adjust
them to
meet
the
specifications
of Table
8-1.
Mounting screws
when A > B
x 100 (0%)
Fig.
9-2
Radial
Alignment
Waveforms
(CATS
EYE)
Fig.
9-2-1
Stepper
Motor
Mounting
Screws
9.7 Azimuth Verification
(1)
Insert
an
alignment
diskette.
Seek
to
the
track
specified
in
the
azimuth
column
of
Table
8-1.
(2)
Set
the
oscilloscope
in
the
same
conditions
as
in
section
9.3,
and
set
horizontal
deflection
to
0.5
ms/division.
(3) Measure as shown below.
(4)
Confirm
that
the
measured
value
meets
the
specifications
in
the
azimuth
column
of
Table
8-1.
When B- C When B>C When B<C
Azimuth = 0' Azimuth = B-€ x (A) Azimuth = CB. x (A)
B-D C-A
(A): 12°
Fig. 9-4 Azimuth Waveforms

9.8 Index Burst Verification and Adjustment
(1)
Insert
an
alignment
diskette.
Seek
to
the
track
specified
in
the
index
burst
column
of
Table
8-1.
(2)
Set
the
oscilloscope
in
the
same
conditions
as
in
section
9.7,
and
set
horizontal
deflection
to
50us
/
division.
(3)
Check
that
the
time
from
kis
iela
start
to
the
first
data
meets
the
index
burst
specifications
of
Table
8-1.
(4) Ifthe specifications are not met, adjust as follows.
eLoosen
the
index
detector
mounting
screws
enough
to
free
the
assembly.
e
Adjust
the
timing
to
meet
the
specifications
of
Table
8-1.
e Retighten the screw.
«Check the timing again.
Fig.
9-5
Index
Timing
Fig.
9-S-1
Index
Detector
9.9
Track
0
Sensor
Adjustment
IMMA
(1) Setthe oscilloscope as follows.
TRIG | SYNC VERT | HORIZ
(2)
Step
between
specified
tracks
at
in
the
track
0
item
of
Table
8-1.
(Turn
the
seek
delay
switch
on
the exerciser
to
adjust
3
ms
seek.)
(3)
Loosen
the
track
0
sensor
screw
and
Pent
until
the
waveform
on
thë
oscilloscope
appears
as
shown
i
in
Fig.
9-6.
Għ
Mounting screw
Fig.
9-6
Track
O
Waveform
` |
Fig.
9-6-1
Track
0
Adjustment
- 10.-

9.10 Asymmetry Verification
(1) Inserta work diskette.
(2) Step tothe track specified in the asymmetry item of Table 8-1.
(3) Setthe oscilloscope as follows.
SYNC VERT | HORIZ
(4) Write 1F.
(5) A read waveform is displayed on the oscilloscope as shown in Fig. 9-7.
(6) Confirm if it satisfies the value as shown in Fig. 8-1.
CH 1
CH 2
Fig. 9-7 Asymmetry Waveform
sil-

10. TEST POINTS
Printed Circuit Board
(Top View)
GND Vout Vout
- STEP - READ
DATA
-12-

11. PANASONIC ALIGNMENT DISKETTE
Table 10-1 Panasonic Alignment Diskette
Index
a
Radial
817-128
34
TRK
34
TRK
16
TRK
JA-551
JU-455
-13-

PART. ll
12. REMOVALS AND INSTALLATIONS
12.1 PCB Removal and Installation |
A E Caution of the cable leading
(1) Remove the four shield plate mounting screws
and take out the shield plate.
(2) Remove the one PCB mounting screw. Let the cable pass under the C guide. Hook the cable to the
(3) Disconnect the connectors (J3 CON, J4 CON, J5 rib projected on the
CON, 17 CON, J8 CON) from the PCB.
(4) To reinstall, reverse the above procedure.
(5) Readjustment is not necessary after PCB ía ' 60 The cable shall not
replacement.
protrude
above
A
the
upper
face
of
the drive. (Make it
flat by pressing
with a finger.)
Do not let the pig
tail bitten or
disconnected.
Do not damage or
disconnect the pig
tail by pressing it
forcibly into the
much in the PCB.
Fig. 12-1-2 Cable Leading
12.2 FrontPlate and Handle Removal and
Installation
| `
U |
y
li
li
Í fire
| +
U
(1) Operate the lock cam of the clamp assembly,
and turn the clamp handle in the direction of
clamping.
(2) Remove the clamp handle.
(3) Remove the two front plate mounting screws,
and take off the front plate.
(4) Reverse the above procedure to reinstall.
Lock Cam
Fig. 12-1 PCB Removal
Clamp Handle
Fig. 12-2 Front Plate and Handle Removal
-14-

12.3
Track
0
Sensor
Assembly
Removal
and
12.4
Collet
Assembly
Removal,
Installation
and
Installation Adjustment
(1) Remove the shield plate as described in section (1) Remove the cartridge guide assembiv as
12.1 step (1). described in section 12.7.
(2) Disconnect the J3 connector from PCB. (2) Remove the lifter unit as described in section
(3) Draw out the pins the track 0 sensor assemblv 12.12
from the following locations on the J3 (3) Remove the collet assembly from the guide
connector : No2, 4, 6. shaft.
At that time, draw out the pins with lifting the (4) Reverse the above procedure to reinstall.
stopper on the connector. (5) After reinstallation, perform collet assembly
(4) Remove the track 0 sensor assembiv mounting center adjustment.
screw and take out the track 0 sensor assembly. (6) Collet assembly center adjustment.
(5) Reverse the above procedure to reinstall. a) Temporarilv fasten the cartridge guide
(6) After reinstallation, adjust the track 0 sensor as assembly.
described in section 9.9. b) Inserta diskette or dummy diskette and
clamp it.
Track 0 (Blue) c) Clamp repeatedly a few times to find a
Track 0 (White) good fit between the collet and the inside
Track 0 (Yellow) diameter of the drive motor.
d) Bind the screws of the cartridge guide.
e) Check step c) again, if not good repeat step
a) through d) until the correct center
adjustment is achieved.
Stopper 1
Collet Assembly
.12-4 Collet Assembly Removal
Fig. 12-3 Track 0 Sensor Assembly Removal
-15-

12.5
(1
(2)
(3)
(4)
—
Clamp Assembly Removal and Installation
Remove the front plate as described in section
12.2.
Remove the shield plate as described in section
12.1 step (1).
Remove the two clamp assembly mounting
screws and take out the clamp assembiv.
Reverse the above procedure to reinstall.
Clamp Assembly
Fig. 12-5 Clamp Assembly Removal
-16-
12.6
(1)
(2)
(3)
(4
—
(5
—
(6)
(7)
(8)
Write Protect Sensor Assembly and Index
Sensor Assembly Removal and Installation
Remove the shield plate as described in section
12.1 step (1).
Disconnect the J3 connector from PCB.
Draw out the pins of the write protect sensor
assembly from the following locations on the
J3 connector : No9, 11.
At that time, draw out the pins with lifting the
stopper on the connector.
Draw out the pins of the index sensor assembly
from the following locations on the J3
connector : No5, 7.
At that time, draw out the pins with lifting the
stopper on the connector.
Remove the write protect sensor mounting
screw and index sensor mounting screw
respectively.
Reverse the above procedure to reinstall.
When reinstalling the write protect sensor,
exercise care so that the leads and write protect
sensor will not project from the bottom and
side of the base.
After index sensor installation, adjust the index
burst as described in section 9.8.

12.7 Cartridge Guide Assembly Removal and
Installation
(1) Remove the PCB as described in section 12.1.
(2) Remove the handle and front plate as
described in section 12.2.
(3) Remove the clamp assembly as described in
section 12.5.
(4) Remove the write protect sensor mounting
screw.
(5) Remove the three cartridge guide mounting
screws and take out the cartridge guide
assembly.
index
Sensor
(Orange)
(6)
After
reinstallation,
adjust
the
collet
assembly
index
Sensor
(Red)
asin
section
12.4
step
(6)
and
adjust
the
index
Write
Protect
Sensor
(Black)
burst
as
in
section
9.8.
Write
Protect
Sensor
(Green)
(7)
When
removing
or
reinstalling,
be
careful
not
to damage the carriage arm with the lifter.
index Sensor
Write Protect Sensor
Cartridge Guide
Assembly
Write
Protect
Sensor
Fig. 12-7 Cartridge Guide Assembly Removal
Fig. 12-6 Write Protect Sensor Assembly and
Index Sensor Assembly Removal
-17-

12.8
Stepper
Motor
Assembiv
Removal
and
12.9
Head
Carriage
Assembly
Removal
and
Installation
Installation
(1)
Remove
the
head
carriage
assembiv
as
(1)
Remove
the PCB
as
described
in
section
12.1.
described
in
section
12.9.
(2)
Remove
the
one
pig
tail
clamp
mounting
screw.
(2)
Remove
the
two
stepper
motor
assembly
(3)
Remove
the
two
guide
rod
clamp
mounting
mounting
screws.
screws.
(3)
Remove
the
stepper
motor
and
stepper
motor
(4)
Remove
the
head
carriage
assembly,
guide
rod
stopper.
clamp,
guide
rod,
and
pig
tail-clamp.
(4)
Reverse
the
above
procedure
to
reinstallation.
(5)
Pull
out
the
guide
rod
from
the
head
carriage
(5)
After
reinstallation,
adjust
the
radial
alignment
assembly.
and
track
0
sensor
as
described
in
section
9.6
(6)
Reverse
the
above
procedure
to
reinstall.
and
9.9.
(7)
After
reinstallation,
adjust
the
radial
alignment
and
track
0
sensor
as
described
in
section
9.6
Stepper
Motor
Assembly
and
9.9.
Head Carriage Assembly
Guide Rod Clamp
Stepper
Motor
Stopper
Fig. 12-8 Stepper Motor Assembly Removal
` Fig. 12-9 Head Carriage Assembly Removal
-18-