Panasonic JU-455-5 User manual

Panasonic
ORDER NO . MSD850902 900
Flexible Disk Storage Drive
,,",U-455-5
Matsushita Communication
Industrial Co., Ltd.
Memory Systems Division
3-1, 4 -c hom e, Tsunashim a- Higashi
Koh
ok u -k u, Yokohama 223 JAPAN

CONTENTS
PA RT I
1.
INTR ODUC T IO N "- ..•.••.••...••..•••.••.....••.•..•.. .. ... ... •... .••• ••...••..•....•... .... .. ...•. . ...• .. •••.. ••....•.••. •. ••.•.
2. MO DE LS AND MDOOEL NUMBE RS ..................................................... ... ............. .... ................... .
3. SP E CIAL TOOlS ·············· · ········ ·········· ················ ......... ..... .......................................... ... ... .... .. .
4.
5.
••
7.
••
g.
10.
11 .
OUTLINEOF MAINT ENANCE .• .••. •.•..•• .•••....•...••...•. . .••..•.. • ••...•....• .•.
DI AG NOS TI C PRO CE DURES . .................. . ..... . ......... ..• .. ... ..... . ..... .. .. ..... .... ........... . .... ....... ........... ..
5.1 Error Symptom Recognit io n ...... ...... ............ .. ................ .. ...... . .. .... ........... ...... ...... ....... .... .
5.2 50
ft Error Detection and Correcti on ....... .... ....... ........ .. . ..... ........ .......... ......... .. ................... .
5.3
5.4
Write Effor . ............. .. ......... . ...................................................................................... ..
Read Error ... . ... ... ... ........................ .. ... ....... .. ..... . ................. .. .... .. . .... ........ ......... .
5.5 Seek. Effor .... ... ... .... . ....................... .... . .. ..... .......... . .. . ............ .. ... ... .... ..
5.6 Comp
at ibili ty Error .. ... .......... ... ............ .. .... . .......... . ...... ....... ................. . ............. .
TR OU 8LE AN ALYSIS ........................ .. ............. .. ..................................................................... ..
6.1 Tr ouble AnalysIs Procedure .. .................... -.. ......... . .............. . ........ ...... ... ..... ... .. . ... ..
6.2 Trouble Shoo ti ng .. . ... .... . ....... ..... ........ .... ...... ........ .. .... .. .. ... ............ .... .... . ......... . .... .
6.3 Trouble
Analy~is T able ' .. .......... .... ........ ... .. . .... ... ............ .. ... ...... .. .. . .......... . .... ... ...... .. .
PR EVEN TI VE MA INT EN ANC E .. ....... . ..... . ............................... ... ....... .. ... ...... ........ .... ...... ..... .......... .
MEASUREMENT I
TEMS F OR EA CH MODEL ... ................................ . .. ........ ........................................ .
AD JUST MEN TS AN D VER I FICA T IONS .. .... .............. ... ........... ...... .. .. ... .. ........ ..... ......... ... ... .... . ..
9.1 Mo tor Speed Adjustment and V erif ication (Inde~ Period) . ........ ... ... ..... .. . ... . ... .... . ..... .... .... ..
9.2
Write Protect Verification ...... .. .............. .... ............ ... ............... . .... . ....... . .. . .......... ..
9.3 Head Output Verif ic ation ....... ... .. . ........... . ............... .... ...................................... .
9.4
Outp ut M odulation Ve rif icati on . ....................................................................... ... ......... .
9.5
Ra di al Alig nmen t Adjustment . ... ......... ... .. . .......... . .. ............ . ... . ....... .. ... ..... . .. . ............... .. . .. .
9.6
Azimuth Verifi cation .. .... . .. ... .. . ..... .... . .. ... ... . .. . .. ...... . ................ . ............ ... .................... .
9
.7 Inde~ Burst Ve ri ficatio ns ...... .. .... .... ...... ... .. . . .... ....... .. ........... . .......... .. ..... . ..... ............. ... .
9.S Tr"c~ 00 Sensor Adjus tme nt .... · .. ·· ...... ··· .. ···· ·· ............ .. .... ............. . ............................... . .. .
9.9 Limiter Ve r ificatio ns (5.25·inch) .... ·................... ......... .. ........ ..... ............ ......... .... . ....... .
9.10
li mi ter Adjustment (3 .S·inch) . .................... .... ........... . ............................... . ......... . ... ..
9. 11 Asymmetry V erific ations ..... .... ... .. . ......... ... ......... . ..... .. ... .. ... ....... .... .. ... . ..... . ... .. . .... .
PANASONICA LI GN ME NT DISKETTE ............. ...................... ... .. ........... .... ..... ............ . .... .
PAR T!!
REMOVALSANDINSTALLATIONS .. · .... ··· .... · .. · ............ · ........ .. ...... ...... ..... .. ............................ ... .... .
1
1.1 P CB Removal and In5tallatlo(\. .... .. . .. .......... ... ............... ... .......... ... . .. . .. . .................... ... ... . ... ..
1
1.2 Front plate Removal and Installation .............. . ........ . ... ... ............................. ..... ... .. ............. .
11.3 Trac
k. 00Assembly Removal and Installat;on· .. · .... .. · .. · ..... .. · .. · ......................... .... .................... .
11.4 CollectAssembly Removal, Installation and
Adjustment ... . .. ...... ......... ... .. . ..... .. ... ..... ................. ..
11 .5 ClampAssembly Removal and Installat io n ......... . ......... . ........... . ........ . .......... ... ........... ..
11 .6 Wr i te Pr otect Sensorllnde~ Detector Ass e mbly Removal and Installati on . ... ..... . ....... .... .•...... . .. ...... .. .
11
.7 Cartridge GuideAssembly R emo va l and Installation ......... ..... .......................... . .. . ................. . ... .
I I .S Stepper Motor Assembly Rem Ov al and Installation ........... ..... ............ ....... .......................... ..... .
1
1. 9 COlIrr i age Arm Assembly Removal and Installation. .......... ... ....... .. ... .... . .. . ........ ...... ....... ..... ... . .... .
11. 10 Drive Motor Removal and Installation .... .. ... . ... .......... .. ... ...... .. ... .... . .. . ......... .. ............... . ...... .
,
1.11 LED As sembly Removal and Install at ion ......... ... ...................................... ...... . .......... ..... ... . ..
12. TE STPOINTS .... ..................... ....... ...................................................... . ................................. .
13. EXPLODED ViEW·
.. ··· .. · .... ·· · ...... ···... · .. .. ........................................................ ..... ........ .. ........ .. . ..
14. REPlACEMENT PA RTS LI ST ........... . ...... . ....... ..... . .. .. ... ... ... .... ..... .......... ..... . .... .. ...... .. ...... .......... . .. ..
15. REPLACEM E NT PART S LI ST OF PC S ...... .. .... .............. . ............. ..... .......... ..... ............ ..... ........... . ..... ..
16. SCHEMATICDIAG RA M ........ ............. ............. .... .... .......... ............ ...... ....... .... ....... ............. ...... ..
17. CIRCUIT BOARD ................................ . .............................. .... .............. .... ......................... ..... ..
lB . BLO CK DI AGRAM ... .......... . ................... ........... ......... ...... ....... ............. ..... ........................ ..... .. .
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r
r
PART. I
1. INTRODUCTION
This service manual consists of tw o parts, Part I covering mainten<lnce de scrip tion, adjustment procedures, and trouble
anal ys is lm d Pa rt II disa ss e mbl y and reassembly procedures parts list, and PCB circuits.
Pa rt I encom passes ma in tenance in nruct ions for a ll FDD models. Refer to the app lic ilb le items, lind perform maintenance
w or k on the FOD.
2. MODELS AND MODEL NUMBERS
2.1 5.25·inch FDD
2.2 3.S-inch FOD
~'2'I .. ~~~'~'~'~'J--,- - 48TPI --'L-- JA ·SSX
JU.455
JA· 550
LJA . 551
l . 5-i nch FOO
96TPI -- ,... __ JA .56X ---, -- JA· 560
L-
JA• 561
JU · ssx - - CL - -JU. 581
JU·S85
JU·59)( - --,-- JU· 59 1
L-
JU.595
61 .STPI - -- - - JU ·31)( -r= JU · 312
JU-313
JU·] 14
135TPI I JU':,2X
LJu .
J6x
-r=
JU.322
JU·323
JU- J24
-r=
NJ6'
JU-363
JU -3 64
3. SPECIAL TOOLS
The fo l lo wing spe cial too ls are u se d fo r FDO mai nte nan ce .
TABLE 3.1
Part No.
To ol
S . 25 ti n~ht~T P ~
5.2S.,nch(95TPI)
'. · '6 . 'IU"U
, .. · sa ", . <1, .... "
Exerciser
F D D·Ex:r~ · S
.. ~
,. ~
Alignment disk ett e I 817-128 817-560 I817·581
.,
Wo rk diskette , 2D,
~ ' . ~ ,
2DD 2 HD
.
---- ----
CMOSm Ladap tor
AI'"
Li mmiter Adfust Tool
(S.25-inc
l-l)
;;.
,
Osci lloscope ( SO MHz)
.,'
Pr obe (10: 1) " . , ;;$l
Frequency counter . -
"f'"
Note: *" _:Stand for the sam e as lett.
: DAD (Dynam ic Alignmen t Diskette) - 1 -
3.S-inch Quan
ti ty
"'~
1
JU .(I1 AA
1 -2
(DAD on ly )
2DD
1-2
YTFDD-CN35 1
1
1
3
1

4. OUTLINE OF MAINTENANCE
• The following tools ate required for maintenance of a Floppy Di sk Dri ve. (FOO)
4.1 A lign ment D iskett e
Alignment diskette is used for nead actuator ali gnment and indexsensor adjustment.
• Ad;tiume nts (R efer to table 8. 1)
(1) Specify an appIJc able model fr om label 8.1. CInd make a readlwrite head radial adjustment at a specified tr ac le .
(SidesQ,l)
(2) Make an iodell timing adjustment at a specified Irack. (Sides O. 1)
(3)
Make iH I azimuth measurement at a specifi ed tracl e (Sides 0, 1)
CAUTION
Do not write when using alignment diskette.. Check that write protect sens or is properly operating .
4.2 Exerciser
The exerciser enables you to make all ad justments an d inspections necessary for an FDD. Its functions include the
follow ing:
(1) Seek increment or alternate tracks
(2) Read
(but no da ta compare)
(3) Write 1F or 2F (AIIO'sor " s)
(4) Head load (S.2S- i nch FDD with optional head loader)
(5) Recalibration to track 00
The exerciser has switches and indicators to execute a specified function .
5. DIAGNOSTIC PROCEDURES
5.1 Error Symptom R e<o gnition
Er ro rs tha t occur because of the wrong operating procedure, wrong programming, or use of a defective diskette, or soft
erro rs due to external causes, such as contaminated air and random electrical noise, are often attributed to a drive
failure
or maladjus tment.
Unless a visual inspection of the dri ... e reveals an evident auembly fault or II defect,always confirm errors with another good
diskette, and another known good dr i ... e.
5.2 Soft E rror D etectio n and C orrectio n
Soft errors are normally caused by th e following:
(1) Contamination between read I write heads and diskette.
This kind of cont.}:,lination can be easily ehminated by the liner in
the d is ke tt e.
(2) Random el ect r ic al noise, normally a f ew mi croseco nds or less.
(3)
Small defects in wri tten data a nd l or tfaclr. not detected du ri ng write oper at ion may cause roft errors dur in g read.
(4) F
aulty grounding of the dr .... e or host system can also cause a soft er ro r.
(5) Wrong
motor s peed is another cause of soft errors.
Take the following
st ep s on the controller side to recover from the soft errors ment ioned above.
(1) Read
the track again ten tim es or unt il th e data is recover ed .
(2) If
Step (1) above fails to recover the data , access the adjacent. Then return the head to the origin al track.
(3) Repe
at Step (11 .
(4) Any
error that cannot be corrected by th e above procedure is irrecoverable.
- 2 -

5.3 Write Error
If an error occurs dur ing write operation, it is usually detected during the next revoluti on by performing a read opera·
ti on called wri te check. To correct an error , write again and r epeat a write check operation. If the result is unsatis-
factory after ten or more write operations, perform a read oper ation on an other tr ack to determine whether it is the
diskette or the dr ive that is wrong. If an error persists, replace the d isk ette and repeat the above procedure.
If th e error still persists, consider the dr i ve defect iv e. If the error is corrected , dispose of the di skette as defective.
5.4 Read Error
Most read errors are soft errors. Da ta can be re covered by fo ll owing the recovery procedure me nt ioned in 5.2.
5.5 Seek Error
(1) Stepper motor or stepper motor dr i ve cir cuit is faulty.
(2) Faulty ca rriage
There are
two ways of seek error recovery. One is to recalibrate to track 00, and seek back to the original track.
The
other is to read the 10 field, check the track number on whi ch the head is located, and move the head away
from it. And read it again.
5.6 Compatibility Error
The data which is written by one drive may not be read by another . Th is error is called a compatibility error, which
can be c.,used mOitly by
the fonowing. The check points are ., Iso m en tioned below:
(1) Head mi salignment: Refer to (Adjustments and Confirmation I tem 9.5)
(2) Head o utp ut too low: Refer to (A djustments and COnfi rmation Item 9.3)
(3) Motor speed difference: Refer to (A djus tments and Confirmation Item 9.1)
6. TROUBLE ANALYSIS
To determ ine the cause of troub le whether it lies in th e FDD , diskette, or contro ller, replace the disk and FDD wi th
good ones. If the FDD is assumed faulty as a re sult, follow the proce dur e below.
6.1 Trouble Analy sis Procedure
FDD troub le may occur in any of the following ten forms.
(1 ) Index detection failure
(2) Not ready
(3 ) Track 0 unde te cta ble
(4) No seek
(5) No write
(6 ) No read
(7) Read err or
(8) IN U SE LED won 't light.
(9) Write protect undetectable
(10) No head load 15.25 ·inch FDD with opt ional head loader)
Check
with the tro ubleshooting flowchart in 6.2.
CAUTION:
Be s ur e to s witch power off before r emoving an FOO or PCB from th e op era ting svnem.
- 3 -

6.2 Trouble Shooting Flow Chart
ST ART
- 4 -
Set Addru. SW
10 Track

6.3 Trouble Analysis Table T
ab le 6.1
Item Trouble N
o. Cause S.2S·j'
ndi
JU-3x3
,..
JU- 3x2
1 Index
detection 1 Collet art fault R.
lace, ,
fai lure 2
DO motor (Ontlol PC B ~ ~eploce Replace DO motor . Replace
00 motor
~liIpllM':e : : :~: :
Base assembly
assemblV
3 DO motor faulty
4 Index LEO faultv
f':Il!'pl<IC!, : :\:
Replace DO m oto r.
5 Index
detector faulty ReP
laCe : :, :,:, :: : Base
assembly
Replace
6 Index LEDlindex det!!Ctor i ns tallation faultv Adj, ,
7 PCB motor ON circuit R'epalr
*,
-
*:
-
•
PCB index detection circuit Repair , , ;i, -
>;,
-
2 Not ready 1 See I tem 1. '?
... .
2 PCB ready circuit
Rep~ir
'.'
*,
-
,; ,'
-
3 Track 0 detection
1 Track 00
a~5embl y
:', .AeplltC!I
!!i
-
if . -
failure 2
PC B Irack 0 detection failure Rapai,
* < :!, -
4 Na head loading 1 See Item 1,
N, . 'CA? ).
2 See Hem
2,
3
HOL solenoid ::: ReP t~e
:(
4 PCB HDL tircuit
Repair >;(
-,
..
<
5 Na seek ,
Stepper motor
Rep hke ""''-::~
)"
-;;; -
2
Guide shaft (Ontamination or damaged
Rep ix .e :: :)
ii ~ <
)"
-
3
PCB stepper dr i ver circuit
'Repai'r rh<W ;-"
-
::' . <
6
NoWR ITE , See Item 1. i
·'
•• ••
2 See Item 4.
\iF'
'" .,.,
3 Head disconnected R.epface ,
:: ; -
3;:
<-
4 Hlilad shorted Replace ' ::' :
,::
-
:!'
-
5
HDL bail height wrong
Adj :=: '
6
PCB write circuit
Aepai~
,
:,s : < ; , ~
-
7 No READ , See Item 1. .. ... .
2 See Item 4.
.,.
,. ,,' .
3 See Item 6. .. '
4 PCB read circuit Rep'air ,,&
1' \ -
'"
-
• READ ERROR , See Item 1.
.... .
2 See Item 4.
'I' \ .•.• ,
3 See I temO" . , ' .
..
4 Alignment Adj. ..
.... ;:; -;;, -
5 Azimuth ,Uiladju uable
,i ; -;:: <
6 Burst
Ad( ,' ? Unadjustable UnlKljUSlable
7
Asymmetry
AOj . Adj.
• Limiter UQadjuSfable
:; Adj. Adj.
, Fl
agO
'Adj,
>; : -'" <
10 HOl time p,dj , '"
" Index period
~dj , ; ,
•... ".:',.
Replace DO motor,
Replace
Base ;5Ssembly
12 PCB read circuit Repair' :;: <
;-So
-
, IN USE
lEO
, LEO
part
fI"plece ':"" .-.~ m -~ -
won't light. 2
PCB IN USE circuit Repair
.i
,, : -
'0
Write protect , Write protect part
fI~l8(;e
R.plK O DD_. ...
Replace
.... '"
failure 2
Wr ite protect circuit
.'~
., :I: -
,,~
-
Note: ii, (- : Sta nd for the same as lett.
7. PREVENTIVE MAINTENANCE
No pr eve nt ive m ai nt enan ce is n ecessary far any type of FODs und er normal cond i tio ns of use.
- 5 -

8. MEASUREMENT ITEMS FOR EACH MODEL
T ab le 8.1
•• m P aramete r
JU -312, 313,314 JU·32X,36X JU-581,S85
TRK
Value T
RK
Value TR K Val ue
1 Index
period
20
200t3ms 40 200 ± 3ms 32 166.7 ;!;
0.2 m5
2
Output level 39 16OmVor
7'
180mVor 76 120mVor
more more more
, Radial
Alignment 20
75"
40 50% 32 70%
4 AZIMUTH 20
± 1 8'
40
± 18 ' 68 ±
18 '
5 Index
burst 20 3±1.5ms 40 3±1.5ms
68 200 t
200 III
6
FLAG 0 From track 1 ' ;1 From
track 1
1: 1 From track 2 1:1
totTack 2 totra,k 2 totTack 3
and back and back. and back
7 limiter -1 Recalibrate -1 Recalibrate - 1 Recalibrate
and return to and return to and return to
0 0 0
• Asym
metry
,.
<6oons 7.
<600ns
76 <3 50 ns
• Head load time
<5 0m5
JU -591, 595, 475 JU-45S/465 JU-455·5
• • m Parameter
TRK VALUE TR K Value
TRK Va lue
1
IndelC period
32 166.7;!; 16132
200± O.2 ms
16 200±0.1 ms
0.2 ms
200t
(High)
0.2 ms
c) •
(Low)
.... ,
2 Output level 76 120 m
llo(
39n9
140 1 120m V
,.
140/mllor
more
or m ore
more
, Radial
Alignment
32
70% 16132 70%
"
70%
4 AZIMUTH 6.
± 18'
311/68
t 18'
34 ± 18'
5 Index
burn
6.
200t 311/68 200t
34 200 t
200p.s 200 }ls 200jU
6 FLAG 0 From
track 2 1:1 From track 1 1: 1 From track 2
,; 1
to track 3
to track
totrack 3
and back
2ltrack 2 to and back
track 3 and
back
'C<.
7 Limiter
-1 Recalibrate -1 Recalibrate -1 Recalibrate
and return to
and return to arid return to
0 0 0
•
Asymmetry 76 <350 ns
39n9 <600 n$ 3. <600",
•
Head load t i me <50 m$ <50ms
i"
. ...
- 6-

9. ADJUSTMENTS AND VERIFICATIONS
9.1 Motor Speed Adjustment and Confirmation !Index Period)
(1 } Insert a diskette, run the motor , and damp , Ref er to the in de x period column of Table 8.1 for th e a pp lica bl e
model.
(2) Step to the specified track.
(3 ) Connect a fre qu en cy co unter to the INDE X signal.
. 5. 25 ,-inch: TP7
3.5·inch: IX
(4) Check that the fr equency coun te r readings meet the specifications in the t ab le.
(5) Adjuum e nt
5.25- inch : Turn the spe ed contro l po tent i ometer on the motor control circuit bo ard unt il the spedf i c:at isons are sat is fied.
3.5 -i nch : No adjus tment
9.2 Write Protect Verification
(1) Check that the exe rc iser's write protect lamp go es on and oft as a media is inserted and removed as speci fi ed in the
table below.
Media wi th write pr ot ect Media wi th write p ro te ct
hole ope n hole clos ed
S.2.S-inch OFF- ON
3.5·inch ON OFF
9.3 Head Output Verificat i on
Use a new diske tte i1 possible to id entity head failure fo r thi~ check.
(1) Insert a good diskette.
(2) Run the motor .
(3)
Step to the t ra ck specified in the o utpu t level column of Table 8.1.
(4) · C onnect th e oscillos cope probe as specified below.
C H1 CH2 E XT
S.2S ·i nc h l Pl TP2 TP7
3.5·" lC h T1 T2 "
UN DE X}
Invert channe l 2 and select the Add mode.
Set vertical deflection to 10 mV/divisi on and horizontal deflection to 20 ms/division.
(5) Write 2F (a ll ones) on the entire circumference.
( In caseot a double·sided FDD, repeat it on sides 0 and 1 using SIDE SE LECT.)
(6) Check that the avtrage out put level meets the specificatio ns of Table 8.1. If it does not meet the s pe c if ication s,
refer to Item 7 of the Trouble Analy sis Table.
- 7 -

9.4 Outpu t Modu la tion Verification
Modulation: M is calculated by the following formula.
Vmax-Vmin
M(%) .. )(100 using the value
obtained in 9.3, a nd check that the
Vma)(+Vmin
calculated value
is 20% or less.
_____ _ _____ ~~ ;:::~:.::i 2= ===Ma l(imum Voltage Valve: Vma)(
-------~----~- ----""" 7% Average Voltage
Minimum Voltage Valve: Vmax
Fig. 9.1 Modulation
9.5 Radial Alignment Adjustment
Introduction
This adjustm ent Isnormally not necessary.
rf the mounting screws for the stepper motor loosen, Of if partsbecome defective, or it a wmpatib i lity erroroccurs, check and readjust
according
to the following procedure.
Ste~ (4) to (9) should be performed regardless of the type, CE or DAD alignmentdiskette used. Use an alignment'diskettesuitable to
the type of FDD to be adjusted according to table 3.1.
(1) Insert an alignment disk ette.
CAUTION :
Be sure to 1"lIe th, ,Ullnm..,t disk.n, under room conditions tor 20 mi nutes b,tor ' , dju,'m,nt .
(2 ) Step to the track specified in the Radialalignment column of Ta bl e 8.1.
(3) Leave the oscilloscope in the same condition as mentioned in section 9.3 .
• Cat s Eye System S. lS -inch
(4) Check the out put wavef orms for sides 0 and 1. Th ey should appear as in F ig. 9.2.
(5) The two wave form s shou ld app ear in the amp li tude ratio in th e R/A co lumn of Table 8.1 or better .
(6) If
the specified ratio is not satisfied, loosen the two mounting screws for the stepper motor.
(n Move the s tepper motor along the base by hand until the two waveforms a ss ume approximately the same a mpl i·
tude, and retigh ten t he mou nt ing screws. (See Fig. 9.2 .)
(8) Step the head outward (track 0) a nd inward ( tra ck 40 or 79), and confirm t hat the adjustment has been c ompleted .
(9)
After the rad ia l adjustment, be sure to con firm trac k 00 sensor adjus tm ent 9,8 and carr iage li mi te r 9.9.
- 8 -
•

r
/
r /
1/
1\
r \
'\,
Fig. 9.2
-
1'-. / I'
1\ / -
A \ B \
/ i\ J
V \ -
V
'\
L-V
-
Radial Alignment Waveforms (CATS EYE)
A > B
B>A
_l
-A
_ A
-S
)( 100
II lOa
Nota: Sides 0 and 1 a,.. adjusted to agree at the 'actofY . If they disagree, adju" them to meet the specifintions of Table 8.1
• DAD (Dynamic Alignment Diskette) 3.5-inch
(4) Watch the output wave form s for si des 0 and 1. They should appear as shown in Fig. 9.3.
(S) Mea sure the timing levels Al to A4 and 81 to 84 in Fig. 9.3, and calculate the lobe ratio from the following
formulas.
EB
}:A x100%
EA
~ A < EB: EB x 100%
(6) The lobe ratio ulwlated by the above formulas should meet the specifications on item 3 of Table 8.1.
(7) If the above requi rement is not met, loosen the two mount ing screws for the stepper motor, adjust.
(8) Seek from track 0 to track 40 and from track 79 to track 40, and confirm that the adjustment has been completed.
(9) After the rad ial adjustment , be sure to co nf irm track 00 sensor adjustment 9.8 and head (arri age li~iter 9.9.
Note : An alignment instrument for 3.5-inch FOOl permits accurate and easy adjustment because the lobe ratio is displayed on
the instrument.
[J,-------------------------u--
Fig. 9.3 Alignment Waveform (DAD)
- 9 -

9.6 Azimuth Verification
(1) Insert an alignment d is kette . Seek to the track specified in the azimuth column of Table B.l .
(2) Set the osc
ill oscope in the same conditions as in B.3, and se t horizontal deflection to 0,5 ms/division.
(3) Measu
re as shown below.
(4) Confirm that the measured value meets the specifications in th e azimuth column of Table B.l ,
B c
B C c o A B
A 0 A
:!
A )!, mu(h 0 wavefo rm $
CaseofB > C C_ofB < C
o
B- C
Azimuth · B _ D >( (AI
C- B
Azimurh ,. --- x ( AI
C- A
9.7 Index Bu rs t Verification
3.5·inch IAI : CE - 30'
DAD - 15 '
Fig . 9.4 Azimuth Waveform,
S.2S·inch 1M : 12'
( 1) Insert an alignment d isk ett e. Seek to the track specified in the liB column of Table B.l .
(2) Set the oscilloscope time base as follows:
S.2S
·i nch: 50 ps/ di vision
3.5 -i nch: 1 ms/division
(3) Check
that the ti me fr om oscilloscope start to the first data pul se meets the 1/8 specif ic at io ns of Table 8.1. (DAD
system)
(4)
It the specif ica tions are not met, adjust as follo ws. (No adjustment necessary for 3.5·inch models)
• Loosen
the index dete cto r mounting screws enough to free the assembly.
• Adjust the timing to 200 ± 200 psec.
• R
et ighten the screw.
• Check the timing again.
I" Indell. Burst .. /
v
Fig. 9.5 Index Timing
-10 -

•
•
•
•
•
9.8 Track 00 Sensor Adjustment
(1) Set the oscilloscope as follows.
Set h orizontal deflectionto 1 mYdivision.
CH1 EXT
S.2S-in ch TP-8
Tp·12
3.5·inch
zp
SP
(21 Step between specified tracks at in the FLAG 0 item ofTable 8.1 (Turn the seek de lay switch on the exercis er to adjust 12
ms seek.)
(3) loo sen the track 0 sensor screw and adjust until the waveform on the oscilloscope appears as shown in Fig . 9.6.
A
-- + ----
sv
'------- --~------G ND
ADJUST A:B TO 1:1
Fig . 9.6 Track 0 Waveform
g,g limiter Verification (S ; )S:inchr
(a .)
(b)
Seek to track 00 .
Push the carriage outwllrd until it contacts the lim i ter , and recOlIlibrate.
Make sure that the carriage moves inward and returns to track 00.
{el If the carriage does not return to track 00 in Step (b), or if it contacts the limiter of the stepper motor. the stepper motor
assembly must be replated because adjustment is u§eless .
9. 10 limiter Adjustment (3.5-inchl
(11 Seek to track O.
(21 Write 2F data on track 0, and measure read level.
(31 Loosen the limiter mounting screw to free the limiter.
141 Move
the limiter until it just touch es the head carriage on - 1 track. and retighten the limiter mounting screw
securely.
(5) Check th at, when the AE CA L switch on the exerciser is pushed ON, the head returns to track 0 and that the 2F
output level is the same as that measured in Step (21.
9.11 Asymmetry Verification
(1) Insert a work diskette.
(2)
Step to the track specified in the symmet ry item of T ab le 8.1.
(3)
Set the oscilloscope as follows:
CH 1 CH2
S. 2S -inch TP-6
..
II TP' /
3.5 ·inch RD
T1
- 11 -

(4) Write If .
(5) A read walle form is displayed on the oscilloscope as shown in Fig. 9.7 .
(6) Confirm if it 1atisfies the villue as shown in Fig. 8. 1.
-
<:
.--
_ ..
..
.. .-- -- _.
f--
T
Fig. 9.7 Asymmetry Waveform
10. PANASONIC ALIGNMENT DISKETTE
Table 10 . 1.
TP I
PIN
I ndex
Azimuth
Burst
-: ,:
:" 8t7·t 28 : ::.
10 "
'"
34TRK 34 TRK
48 .., -
','
'"
68TRK 68TRK
96 817-560
68TRK 68RTRK
96
817 ·581
61TRK 61TRK
100 817-570
Table 102 . . 3
.5 inch Alignment Diskette
TPI PIN
Index
Azimuth
Bur st
20 20
67.5 JU-0 1AA
40 40
135 JU-01AA
-12 -
•
. ..
•
•
Radial
MODEL
/' 16TRK JA-55X
..
JU·45S
32TRK JA-56X
JU-465
32TRK JU-475 •
JU-58X
JU-59X
36TRK JU-570
Radial
MODEl
20
JU -31X
40
JU -32X
JU-36X •

•
•
•
PART. 11
11 . REMOVALS AND INSTALLATIONS
11 .1 PCBRemoval and Installation ( See Fig. 11 .1)
(1) Remove the two printed circuit board
mounting sc rews.
(2) Disconnect the connecto rs(J3 CON, J4 CON,
J6 CON,)5 CON,J8CON) from the pr inted
circuit board .
(3) Remove the printed circuit board by sliding it
asla nt .
(4) To reinstall, reverse the above procedure.
(5) Readjustment is no t necessary after pri nt ed
circuit board replacement.
Pr i nted Circuit Board
8
Fi g_ 11 .1 Prin ted Circuit Board Removal
11.1-'
J6CON
N ote:
:::el'ese connection prevention pin is n ot provided in 13 and J6 .
,', '-e:': installing the P. e. e. board, connect them so that the white
·c or. !ne B (onnector is fa ci ng upwards and J6 connector pin
',: . - . a:t., es the p.e.B. si de pi n No.
- 13 -
11 .2 Front plate R emova l an d In stallati on
(See F ig .11.2)
(1) Operate the lock cam of the clamp assembly,
and
turn the damp handle in the di rection of
clamping.
(2) Remove the clamp handle.
(3) Remove the t wo front pl ate m ount in g screws,
and take off the front pla te .
(4) Reverse th e above procedure to reinsta ll.
Clamp
Lock Cam
(Clamp Ass'vl
Fi g. 11 .2 Front Plate Removal
11.3 Track 00 Assembly Removal and Installation
(See Fig. 11.3)
(1) Remove the track 00assembly mounting
sc r ew andt ake out the track 00 assembly.
(2) Pull out the wh ite, yellOW, and green wires
from J6CON (lOP).
(3) Reverse the above procedure to reinstal l.
(4) After reinstall at ion, adjust the track 00 sensor
as
de sc ribed in 9.B.
T rac:: k ....o Assemblv
J6CON
Fig. 11 .3 Track 00 A ss em b ly Re m oval

11.4 Collet Assembly Removal, Installation. and
Adjustment (See Fig.11.4)
(1) Remove the Cartridge Guide Assembly as
desc
ri bed in 11 .7
(2) Remove the lifterspring from the lifter.
(3) Remove the E-ring from the lifter shaft.
(4) Remove the lifterfrom the Cartridge Guide.
(5) Remove the ColletAssembly from the Guide
shaft.
(6) Reverse the above pro cedure to reinstall.
(7) After reinstallation, perform colletassembly
cente r adjustment.
(B) Collet assembly cente r adjustme nt .
a) Temporarilyfasten the Cartridge Guide
Assembly.
b) Inserta diskette ordummydiskette and
damp it.
c) Clamp repeatedly a few times to find a
good fit
between the collet and the
inside diameter of the DO motor.
d) Bind
the screw ofthe Cartridge Guide.
e) Check step c) again, if not good rep eat
stepsa) through d) until the correct
center adjustment is achieved.
Col!et A~sembly _____ •
~
•
Fig. , 1.4 Collet Assembly Removal
, 1.5
Cl amp Assembly Removal and In stallation
-14 -
(1) Remove the front plate as described in 11 .2.
(2) Remove the two damp assembly mounting
screws.
(3) Remove the damp assembly.
(4) Reverse the above procedure to reinsta ll.
@
Fig. 1' .5 Clamp A sse mbly Re moval
•

•
•
•
11.6 Write Protect Sensor/Index DetectorAssembly
Removal
and In stallation (See Fig. 11.6)
(1) Remove the front plate as described in 11.2.
(2) Remove
the write protect sensor mounting g
screw
and index detector mounting screw
respectively.
(3) Remove the wri te protect sensor/index
detector assembly.
(4) Reverse the above procedure to reinstal l.
(5)
When reinstalling the write protect sensor,
exercisecare so
that the leads and write
protect sensor will not projectfrom the
bottom and side of the base.
(6) After index detector installation, adjust the
index timing as described in 9.7.
@
Fig.11.6 Write Protect Sen sor/Index Detector
Assembly Removal
11.7 Cartridge Guide Assembly Removal and
Installation (See
Fig . 11 .7)
- 15 -
(1) Remove the printed circuit board as described
in
11.1 .
(2) Remove the front plate as described in 11.2.
(3) Remove the shield plate mounting screwand
ta ke the shield plate off.
(4) Remove the write protectsensoras described
in 11 .6. It is not necessa ry to remove the
index detector.
(5) Remove the four cartridge guide mounting
screws and
take out the cartridge gui de
assembly.
(6) After reinstallation, adjust
the collet assembly
as
in 11 .4 step (6) and adjust the index timing
as
in 9.7.
(7) When removing or reinstalling, be careful not
to damage the carriage arm with the lifter.
Insulating Paper
Shi,'dPlot, ~
~,t-- '
Cartridge Gui de
Assembly
~
<::i \ I
I
Fig. 11 .7 Cartridge Guide Assembly Removal

11.8 Stepper Motor Assembly Removal and
Installation (S ee Fig . 11 .8)
(1) Remove the insulating paper and shield
plate .
(2) Remove the track 00 sensor asdescribed in
11.3.
(3 ) Remove the two (M2 x 4) actuator screws that
fasten the actuato r to the carriage arm
assembly.
(4) Remove
the two (M3 x 6) stepper motor
assembly moun ting screws an d then the
stepper ·motor.
(5) Reverse the above procedure to reinstall.
(6) After reinstallation, perform limiter check as
in 9.
10 an d radial alignment adju stment as in
9.5.
(7) Adjust th e track 00 sensor according to the
ins tru ction in 9.8.
Fii- " .8 Stepper Motor Assembly Removal
-16 -
11 .9 Carriage Arm Assembly Removal and
Insta ll atio n (See Fig.11. 9)
(1) Remove the printed circuit board as described
in 11 .1.
(2) Remove the insulating paper and shield pl ate .
(3) Remove the track 00 assembly as descrj bed in
11.3.
(4) Remove the stepper motor assembly as
descri bed in 11 .8.
(5) Remove the two guide rod clamp mounting
screws.
(6)
Re move the carriage arm assemb ly, guide
rod
damp , and guide rod.
(7) Pul lout the guide rod from the ca rri age arm
assemb
ly .
(8) Reverse
the above procedure to reins ta ll.
(9) After replacement, perform limiter
adjustment as described in 9.10, tr ack 00
sensor adjustment as described in 9.8, and
radial ali
gnment adju stment as described in
9.5.
Gu ~e R . ' ~C- __ ___ . __ ~'
Fig. " .9 Carriage Arm Anembly Removal

•
•
•
•
•
1'.10 Drive MotorRemoval and Installation
(See Fig.11.10)
(1) Remove the printed circuit board as
described in 11.1 .
(2) Remove the insulating paper and shie ld
plate .
(3) Rem ove the front plate asdescribed in 11 .2.
(4) Remove the write protect sensor as described
in 11.6.
(5) Remove the cartridge guide assembly as
de scribed in 11.7.
(6) Remove the three drive motor mounting
screws and take off the drive motor from the
base.
(7) Disconnect the dri ve motor connector pins
from t he connector.
(8)
Re ve rs e the above procedure to reinstall.
(9) When reinstalling, make sure that the drive
motor connector is connecte d in the correct
direction.
(lO)After reinstallation. perform
motor speed
adjustment asdescribed in 9.' and also the
adjustmen ts necessary upon reinstallation of
the cartridge guide as described in 11 .7.
Drive Mo tor
Fig. 11 . 10 Drive Motor RlHTloMi
-17-
11 ." LED Assembly Removal and Installation
(1) Remove the clamp handle and front plate .
(2) Disconnect the connectorsJ8 CON from the
pr inted circuit board.
(3) Remove the lED Assemb ly by sliding it as la nt
from the Cartridge GuideAssembly.
(4) Reverse the above procedure to reinstall.
LED Assembly •
Fig.11." LED Assembly Removal

12. TEST POINTS
Printed Circuit Board
(Top view)
GND
lN TTRK00
Vout(-) Vout(+)
+ READ DATA
STEP
-18 -