IBM 5280 Setup guide

-=- -.:-:. -=- = SY31-0602-0
- ----
- -.. ---
- - - ---
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IBM 5280
Distributed Data
System
Diskette Drive
Maintenance Information Manual

First Edition (March 1980)
Changes are periodically made to the information herein; these changes will be reported
in technical newsletters or in new editions of this publication.
It is possible that this material might contain reference to, or information about IBM
products (machines and programs), programming; or services that are not announced in
your country. Such references or information must not be construed to mean that IBM
intends to announce such I BM products, programming, or services in your country.
Use this publication only for the purpose stated in the Preface.
This publication could contain technical inaccuracies or typographical errors. Use the
Reader's Comment Form at the back of this publication to make comments about this
publication. If the form has been removed, address your comments to I BM Corporation,
Product Information Development, Department 997, 11400 Burnet Road, Austin,
Texas 78758. I BM may use and distribute any of the information you supply in any
way it believes appropriate without incurring any obligation whatever. You may, of
course, continue to use the information you supply.
©Copyright International Business Machines Corporation 1980

This maintenance information manual (MIM) is to be used
to service the diskette drive after it has been removed from
the particular unit of the 5280 system in which it is housed.
Customer engineers using this manual
are assumed to have
completed the 5280 education course.
This
MIM has three major sections: Maintenance, Tools
and Test Equipment, and Theory. Maintenance includes
locations, procedures, and diagnostic aids. Tools and Test
Equipment includes a list
of special tools and test
equipment and the part numbers
of the tools and test
equipment. Theory includes data
flow, functional units,
and features.
Definitions
of terms and abbreviations that are not
common, but are used in the MIM, are in the Glossary of
Terms andAbbreviations.
There are several DANGER and CAUTION notices in this
manual. You can use the blank lines below each notice to
translate it into your own words. The locations of these
notices
are listed in the Safety section.
Related Publications
Related information can be found in the following
manuals:
• IBM 5280 General Information Manual, GA21-9350
• IBM 5280 Operator's Guide, GA21-9364
Preface
• IBM 5280 User's Setup Procedures, GA21-9365
• IBM 5280 Data Areas and Diagnostic Aids Handbook,
SY31-0595
• IBM 5281 Data Station Maintenance Information
Manual, SY31-0596
• IBM 5282 Dual Data Station Maintenance Information
Manual, SY31-0597
• IBM 5286 DualProgrammable Data Station
Maintenance
Information Manual, SY31-0599
• IBM 5285Programmable Data Station Maintenance
Information Manual, SY31-0600
• IBM 5288 Programmable Control Unit Maintenance
Information Manual, SY31-0601
• The IBM Diskette General Information Manual,
GA21-9182
Preface iii

iv Preface

HOW TO USE THIS MANUAL ..
· vii
MAINTENANCE PHILOSOPHY.
· ix
SAFETY ..... . ................... x
MAINTENANCE.
LOCATIONS ...
330 Diskette Drive
331
Diskette Drive Control Card
333 Diskette Drive Control Card Connector Pins.
COLLET ....................... .
335 Collet/Flat Spring Removal and Replacement.
Removal ............ .
Replacement. . . . . . . . . . .
HEAD/CARRIAGE ASSEMBLY.
337 Head/Carriage Service Check.
339 Head/Carriage Adjustment ..
340 Pressure Pad Removal and Replacement (31 SD only).
Removal ................... .
Replacement. . . . . . . . . . . . . . . . . .
341 Head/Carriage Removal and Replacement
Removal
............... .
Replacement. . . . . . . . .
.... .
HEAD LOAD SOLENOID AND BAIL.
343 Solenoid and Bail Service Check.
344 Head Gap Service Check ... .
345 Head Gap Adjustment ..... .
346 Solenoid and Bail Adjustment.
347 Bail Removal and Replacement
Removal
............. .
Replacement. . . . . . . . . . . .
349 Solenoid and Idler Removal and Replacement.
Removal ...
Replacement. . . . . . . . . . . . . . . . . ..
AC DRIVE ..................... .
351
AC Drive Motor Removal and Replacement
AC Drive Motor with External Fan.
Removal ............ .
Replacement
.......... .
AC Drive Motor with Internal Fan
Removal
............ .
Replacement. . . . . . . . . . .
353 Capacitor Removal and Replacement.
Removal ................. .
Replacement. . . . . . . . . . . . . . . .
355 Drive Fan and Pulley Removal and Replacement
Removal
.....
Replacement. . . . . . . . . . . . . . . . . ..
STEPPER DR IVER. ............... .
357 Stepper Motor Removal and Replacement.
Removal .................... .
Replacement. . . . . . . . . . . . . . . . . . .
359 Stepper Motor Pulley and Clamp Removal and
Replacement
..
Removal ...
Replacement.
· 1
· 1
· 1
.2
.4
.8
.8
.8
.8
· 10
· 10
.12
· 14
.14
· 14
.15
· 15
· 15
· 18
· 18
.20
· 21
.22
.24
.24
.24
.26
.26
.26
.28
.28
. 28
. 28
.28
. 30
. 30
. 30
.32
. 32
.32
.34
.34
.34
.36
.36
.36
.36
.38
.38
.38
361 Drive Band Service Check ........ .
363 Drive Band Adjustment ......... .
365 Drive Band Removal and Replacement .
Removal
.......... .
Replacement
........ .
LED AND PTX ASSEMBLIES.
367 Diskette Speed Service Check .
369 LED Output Service Check ...
371 LED Removal and Replacement.
Removal ............ .
Replacement. .
.......... .
373 PTX Amplifier Service Check ..
375 PTX Removal and Replacement .
Removal
.............. .
Replacement. . . . . . . . . . . . .
377 Diskette Drive Control Card Removal and
Replacement
................... .
Removal
.. .
Replacement. . . . . . . . . . .
TOOLS AND TEST EQUIPMENT
THEORY ..... .
Introduction. . . . .
Diskette Description
Stepper Motor. . . .
Operation ....
FM Format Principles
Read Data
.... .
Scope Charts ... .
MFM Format Principles
Read Data
..
Scope Charts.
Volume Label ..
Volume Label Layout
Volume Label Format
Header Label . . . . . . .
Header Label
Layout .
Header Label
Format .
Data Recording
Format
Gap 1 ....
Sync Field .
AM 1 ..
ID Field
CRC .
Gap 2
..
AM2 ..
Data Field.
Control Field
Gap 3.
Gap 4.
Index.
Operation
Typical Timing Sequence
Contents
.........
.39
.40
.42
.42
.42
.44
.44
.49
· 51
· 51
· 51
.52
.54
.54
.54
.56
.56
.56
.57
.59
.59
.59
.60
.60
.62
.62
.63
.64
.64
.65
.66
.66
.67
.70
.70
· 71
.74
.74
.74
.74
.74
.75
.75
.75
.75
.75
.75
.75
.75
.76
.77
GLOSSARY OF TERMS AND ABBREVIATIONS.
.79
Contents v

vi Contents

The information in this MIM is to be used as reference
material
when diagnosing machine failures. This M 1M
contains maintenance procedures, tools and test
equipment information, and theory.
The format for page numbering is XXX.Z. XXX is the
number of the page and Z (although not normally used)
is for expansion when it is not practical to give new
numbers to all pages.
Three-digit reference
numbers are assigned to location
drawings
and maintenance procedures to refer from the
MAPs.
Maintenance Procedures Section
The maintenance procedures section contains location
drawings and maintenance procedures for repairing,
installing, or diagnosing the failing field-replaceable unit.
How to Use Th is Manual
Tools and Test Equipment Section
The tools and test equipment needed to service the diskette
drives are described in the tools and test equipment section.
Theory Section
The theory section contains descriptions of the functional
units and features. These descriptions are preceded by a
view
of the diskette unit which gives you a general idea of
the complete operation and where each function or feature
fits in.
Index
The index is a detailed list of all material in the M 1M and
the pages on which that material is located.
How to Use This Manual vii

viii How to Use This Manual

The diskette drives need no scheduled maintenance. The
MAPs guide you in diagnosing diskette drive failures. The
MAPs refer to maintenance procedures in this manual when
an adjustment, service check, or FRU replacement is
needed.
All maintenance procedures are written with the
assumption that the drive assembly has been removed
from
the enclosure and is fully accessible on a work surface.
It might be practical in some instances, to perform specific
procedures without removing the drive assembly. These
instances can
best be determined by the individual
circumstances.
The head/carriage assembly and the drive hub and spindle
pulley assembly
are adjusted and tested at the factory. The
drive hub and spindle pulley assembly are not field-replace-
able units.
If the track 40 adjustment surface or the drive
hub and spindle pulley assembly are damaged, you should
replace the entire diskette drive assembly. The head/
carriage assembly is a field-replaceable unit.
Maintenance Ph ilosophy
The main differences between the 31SD diskette drive (for
the diskette 1) and the 51 TD diskette drive (for the diskette
1, 2, and 2D) are in the head/carriage assembly and the layout
of the diskette drive control card. Maintenance procedures
that are affected by such differences will provide two distinct
sets of instructions within the affected step. These distinct
differences will be labeled (31SD) and (51TD) as in the
following example:
1.
2.
3.
4.
Remove the cover.
Disconnect
the cables.
(31 SD) Remove
the head/carriage assembly.
(51 TD) Insert a clean piece
of paper between the
read/write heads and remove the head/carriage
assembly.
Invert the assembly.
When
the callout of a figure is not affected by the
difference between the drives, the 31 SD drive figure will be
used. In those instances where the callout is affected by
the difference, the 51 TD drive figure will also be used.
Maintenance Philosophy ix

Safety
The diskette drives contain the following specific
DANGERS:
• Voltages are present on the connector terminals in the
diskette drive.
• Motor and solenoid cases become hot after continuous
use; allow enough time for parts to cool before servicing.
DANGER AND CAUTION NOTICES
Throughout this manual, the word DANGER is used to
inform the CE of an action that could cause a personal
injury. The word CAUTION is used to inform the CE of an
action that could damage the machine, or affect the
running
of a customer program.
Danger Notices
Danger notices appear in the following maintenance
procedu
res:
337 Head/Carriage Service Check
339 Head/Carriage Adjustment
341 Head/Carriage Removal and Replacement
343 Solenoid and Bai I Service Check
346 Solenoid and Bail Adjustment
347 Bail Removal and Replacement
349 Solenoid and Idler Removal and Replacement
351 AC Drive Motor Removal and Replacement
353 Capacitor Removal and Replacement
355 Drive Fan and Pulley Removal and Replacement
373 PTX Amplifier Service Check
x Safety
Caution Notices
Caution notices appear in the following maintenance
procedures:
335 Collet/Flat Spring Removal and Replacement
337 Head/Carriage Service Check
339 Head/Carriage Adjustment
340 Pressure Pad Removal and Replacement
341 Head/Carriage Removal and Replacement
346 Solenoid and Bail Adjustment
347 Bail Removal and Replacement
357 Stepper Motor Removal and Replacement
363 Drive Band Adjustment
365 Drive Band Removal and Replacement
375 PTX Removal and Replacement

CE SAFETY PRACTICES
All Customer Engineers are expected to take every safety
precaution possible and observe the following safety practices
while maintaining IBM equipment:
1. You should not work alone under hazardous conditions
or around equipment with dangerous voltage. Always
advise your manager if you MUST work alone.
2. Remove all power, ac and dc, when removing or
assembling major components, working in immediate
areas of power supplies, performing mechanical
inspection of power supplies, or installing changes in
machine circuitry.
3. After turning off wall box power switch, lock it in the
Off position or tag it with a "Do Not Operate" tag,
Form
229-1266. Pull power supply cord whenever
possible.
4.
5.
6.
7.
When it is absolutely necessary to work on equipment
having exposed operating mechanical parts or exposed
live electrical circuitry anywhere in the machine, observe
the following precautions:
a. Another person familiar with power off controls
must be in immediate vicinity.
b .. Do not wear rings, wrist watches, chains, bracelets,
or metal cuff links.
c. Use
only insulated pliers and screwdrivers.
d. Keep one hand in pocket.
e. When using test instruments, be certain that controls
are set correctly and that insulated probes of proper
capacity are used.
f.
Avoid contacting ground potential (metal floor strips,
machine frames, etc.). Use suitable rubber mats,
purchased locally if necessary.
Wear safety glasses when:
a. Using a hammer to drive pins, riveting, staking, etc.
b.
Power or hand drilling, reaming, grinding, etc.
c.
Using spring hooks, attaching springs.
d. Soldering, wire cutting, removing steel bands.
e. Cleaning parts with solvents, sprays, cleaners,
chemicals, etc.
f.
Performing any other work that may be hazardous to
your eyes. REMEMBER-THEY ARE YOUR EYES.
Follow special safety instructions when performing
specialized tasks, such as handling cathode ray tubes
and extremely high Voltages. These instructions are
outlined in CEMs and the safety portion of the
maintenance manuals.
Do not use solvents, chemicals, greases, or oils that
have not been approved by IBM.
8. Avoid using tools or test equipment that have not been
approved by IBM.
9. Replace worn or broken tools and test equipment.
10. Lift by standing or pushing up with stronger leg
muscles-this takes strain off back muscles. Do not lift
any equipment or parts weighing over 60 pounds.
11. After maintenance, restore all safety devices, such as
guards, shields, signs,
and grounding wires.
12. Each Customer Engineer is responsible to be certain that
no action on his part renders products unsafe or
exposes customer personnel to hazards.
13. Place removed machine covers in a safe out-of-the-way
place where no one can trip over them.
14. Ensure that all machine covers are in place before
returning machine to customer.
15. Always place CE tool kit away from walk areas where
no one can trip over it; for example, under desk or table.
16.
Avoid touching moving mechanical parts when
lubricating, checking for play, etc.
17. When using stroboscope, do not touch ANYTHING-it
may be moving.
18. Avoid wearing loose clothing that may be caught in
machinery. Shirt sleeves must be left buttoned or roiled
above the elbow.
19. Ties must be tucked in shirt or have a tie clasp
(preferably nonconductive) approximately 3 inches from
end. Tie chains are not recommended.
20. Before starting equipment, make certain fellow CEs and
customer personnel are not in a hazardous position.
21. Maintain good housekeeping in area of machine while
performing and after completing maintenance.
Knowing safety rules is not enough.
An unsafe act will inevitably lead to an accident.
Use good judgment-eliminate unsafe acts.
ARTIFICIAL RESPIRATION
General Considerations
1. Start Immediately-Seconds Count
Do not move victim unless absolutely necessary to
remove from danger. Do not wait or look for help or
stop to loosen clothing, warm the victim, or apply
stimulants.
2. Check Mouth for Obstructions
Remove foreign objects. Pull tongue forward.
3. Loosen Clothing-Keep Victim Warm
Take care of these items after victim is breathing by
himself or when help is available.
4. Remain in
Position
After victim revives, be ready to resume respiration if
necessary.
5. Call a Doctor
Have someone summon medical aid.
6. Don't Give Up
Continue without interruption until victim is breathing
without help or is certainly dead.
Rescue Breathing for Adults
1. Place victim on his back immediately.
2. Clear throat of water, food, or foreign matter.
3. Tilt head back to open air passage.
4.
5.
6.
7.
8.
9.
Lift jaw up to keep tongue out of air passage.
Pinch nostrils to prevent air leakage when 'You blow.
Blow until you see chest rise.
Remove
your lips and allow lungs to empty.
Listen for snoring and gurglings-signs of throat
obstruction.
Repeat mouth to mouth breathing 10-20 times -a minute.
Continue rescue breathing until victim breathes for
himself.
Thumb and
finger positions
Final mouth-to-
mouth position
Safety xi

xii Safety

Maintenance
Locations
330 DISKETTE
DRIVE
D Diskette locking lever
fI
Diskette drive control card
IJ
Spindle pulley
II
Head load solenoid
II
Solenoid idler
II
AC drive belt
IJ AC drive pulley (with fan hidden)
D Stepper motor
II AC drive motor
D
lID
Head load bail
mPressure roll
ill
Collet
1m
mCollet
flat spring
II] Drive
hub
1m
Carriage pressure spring
1m
Thickness gauge clip
ED
Stepper motor
Em
Timing pin
Em
Head/carriage assembly
330 Locations 1

331 DISKETTE DRIVE CONTROL CARD
31SD
4 1
~
PTXCP
BA
001
o
00
00
00
00
00
00
00
00 I/O CP
00
o TPB01
DTPA010
TPC040 0 0 0 TPC01
oTPD01
TPE030 0 0 TPE01
TPF020 0 TPF01
TPG02 0
TPH050
o TPG01
O
i~~
TPC
TPD
TPE
TPF
TPG
TPH
00
00
100 D 0 01
TH
00
00
00
00
oTPHLD
0018
o TP24V
IOIB
~A
2 1
LEDCP
TH01
TH02
TH03
TH04
TH05
TH06
o TPLED
SCP
4 1
~
D,jf Read B
Nu Pin
Dill Read A
Not ASSigned
·Dlsable Steppel Motol
+18 V
2 Locations
D
TPA01 -5 Vdc TPG01
TPB01 ·5 Vdc TPG02
TPC01 -<-Access 1 TPH01
TPC02 31S0
PTX
TPH02
TPC03 Wllte Data TPH03
TPC04 Glouno TPH04
TPD01 +Inncr Tracks
TPH05
TPE01
-tAcCt.)sS 0 TPAMP1
TPE02 +Head
Engage
TPAMP2
TPE03 +Inclex
TPHLD
TPF01 Ground
TP24V
TPF02 -tWine Elase Enahll'ci
TPLED
TPH04 0 0 0 0 TPH01
o TPAMP 1
o TPAMP2
DD
7 HCP
1000 0 0 1
+FrJe Data
+Erase Gate
MC-3
MC·2
MC·1
MC·O
+Wrrte Gate
Preamp
TP1
Preamp TP2
·Head Load
+24 Vdc
31SD LED Voltage
331
6 1
10000 01
SMCP

51TD
PTXCP TPA10
5 1 I
~OO 0
00 1 TPB07
o
00
o TPEOI
TPAOS
Do 0 o
TPA06
TPB06 0 0 0 0 0
TPC03 0 0 0 TPCOI
TPD020 OTPDOI
00
00
00
00
00
00
00
00
00
00
00
00
o TPFOI
o TPGOI
o TPHOI
o TPLD2
o TPLDI
1/0 CP
00
00 lB
BA 0
6 1
100 01
LEDCP
THO I
Ddt Read B
TH02 No Pin
SCP
4 1
~
TH03
Ddt Read A
TH04
-HlghGall1
TH05 -Disable Stepper Motor
TH06
+14V
TH07
Access Clamp Voltage
TH08 Oscillatol
--
TPAOI
MC 3
TPA02
MC I
TPA03
MC-2
TPA04
MC-O
TPA05 Glound
TPA06
-E'ase Gdtt'
TPA07 Glound
TPA08
-Head Load
TPA09 +5 Vdc
TPAIO 51T0 PTX
TPBOI +24 Vdc
TPB02 Glound
TPB03 +Select Head 1
TPB04
+Wrrtt) uate
TPB05
+Head Engage
TPB06
Wllte Data
oTPBOl
TH
D
TPB07
TPCOI
TPC02
TPC03
TPDOI
TPD02
TPEOI
TPFOI
TPGOI
TPHOI
TPLD2
TPLDI
TPAMP2
TPAMPI
TPCTO
TPCTI
TPA
TPB
TPC
TPD
TPE
TPF
TPG
TPH
oTPA05
o 00
D
TPAMP20 0 TPAMPI
o TPAOI
6 SMCP 1
10000 01
D
o TPCTO
I·TPCT1
'---1-4--'----:-:H:=CP
1000000000000 01
3150 PTX
-ACCt'sS 0
'lllf)~r TrdCks
-5 Vdc
'Access I
,Switch Flitel
+Index
+Dlskette Sense
+Wrrte
EI ase Enabled
+Flie Data
51T0 LED Voltage
3150 LED Voltage
Prean'p TP2
Prean1p TPI
Center Tap Head 0
Center
Tap Head 1
331
Locations 3

333 DISKETTE DRIVE CONTROL CARD
CONNECTOR PINS
31SD
D
4 i----f------------,
~
PTXCP
BA
4 Locations
o TPBOl
DTPA010
TPC040 0 0 0 TPCOl
o TPDOl
TPE030 0 0 TPEOl
O
i~:
TPC
TPD
TPE
TPF02 0 0 TPFOl
TPF
TPG02 0
TPH05 0 o TPGOl
6
laa a a al
TH
D
TPG
TPH
333
o TPAMP 1
TPH04 0 0 0 0 TPHOl
6
o TPAMP 2
000 0
SMCP

D PTX Connector
II
LED Connector
A01 PTX col (+5 V) A01 ground
A02
blank
A02
not used
A03
PTX emitter
B01 LED anode
A04 not used
B02 blank
fJ
I/O Interface Connector a Solenoid Connector
A01
-5 V A01
not used
A02
power supply ground
A02
blank
A03 - A18
ground
A03
+24 V
801 +5 V
A04 -head load
802
blank
B03 +24 V m
Head Connector
804
+index
805
+diskette 2 sense
A01 ground
806
+write/erase sense
A02 blank
807
+file data
A03 erase coil
808
+inner tracks
A04 blank
809
+erase gate
A05
read/write coil
810
+access 0
A06 read/write coil
811
not used
A07
ground
812
not used
813 +access 1 mStepper
Motor Connector
814
+write gate
815
+head engage
A01 +24 V
816
not used
A02
blank
817 write data
A03
MC-3
818
not used
A04
MC-2
A05
MC-1
A06
MC-O
333
Locations 5

51TO
TPA08 0 TPA06
o 0 0 0
DTPB06 0 0
00TPCOl
TPC030 0 oTPDOl
TPD020
6 Locations
OTPBOl
D
TPA
TPB
TPC
TPD
TPE
TPF
TPG
TPH
D
o TPAMPl
TPIVIIlp2 0
333
.SMCP~
10000 ,

51TO
II
PTX Connector
1m Solenoid Connector
AOl
diskette 1 col (+5 V)
AOl
not used
A02 blank
A02 blank
A03 diskette 1 PTX emitter
A03 +head load
A04 diskette 2, 20 PTX emitter
A04 -head load
A05
diskette 2, 20 col (+5 V)
m Head
Connector
m I/O Interface
Connector
A01
not used
AOl -5 V
A02 blank
A02 power supply ground A03
head 0 read/write coil
A03 - A18 ground
A04 head 0 center tap
BOl +5 V
A05 head 0 read/write coil
B02 blank
A06 head 0 erase
B03 +24 V A07 head 0 erase
common
B04
+index
A08
ground
B05 +diskette 2 sense
A09 ground
B06 +write/erase sense
Al0
head 1 erase common
B07 +file
data
All head 1 erase
B08 +inner tracks
A12
head 1 read/write coil
B09 +erase gate
A13 head 1 center tap
Bl0
+access 0
A14 head 1 read/write coil
B
11
+select head 1 if)
B12
not used
Stepper Motor Connector
B13 +access 1
B14 +write gate AOl
+24 V
B15 +head engage
A02 blank
B16 +switch filter
A03 MC-3
B17 write
data A04 MC-2
B18
not used A05 MC-1
D
A06
MC-O
LED Connector
AOl diskette 2, 20 ground
A02 blank
A03 diskette 2, 20 ground
A04 blank
A05 diskette 1 ground
A06
diskette 1 anode
333
Locations 7

Collet
335 COLLET/FLAT SPRING REMOVAL AND
REPLACEMENT
Removal
1. Power off.
2. If
the diskette drive was removed from an IBM 5282
or an IBM 5286, remove the mounting bracket on the
base of the drive by removing two screws on each side
of the mounting bracket. (This bracket is not
installed for the other data stations.)
3.
4.
5.
6.
7.
8.
9.
Close the diskette locking lever II.
Loosen the bail lever screw 1m.
Push the bail 1m inward slightly and disconnect the
bail actuator cable eyelet Ii from the bail lever 1m .
Open the diskette locking lever.
(51TD) Place a piece
of clean paper between the
heads, or insert a scratch diskette.
Loosen the bail mounting screw II.
Pull the pivot rod II out, then remove the bail and
the bail return spring mby sliding them out from
under the head load arm 'D. (Note the location of
the bail return spring between the bail and the
diskette guide for replacement.)
10. Remove the screw and the nut 1m.
CAUTION
(31SD) Do not let the head hit the pressure pad, or the
head could be damaged. (51TD) Do not let the heads hit
each other, or the heads could be damaged.
11. Remove
the diskette locking lever II.
12. Remove the collet actuator roll II and the pressure
roll II.
8 Collet
335
13. Turn the collet actuator rod 1m up and out of the
way.
14. Remove
the colletlflat spring assembly D .
Replacement
1. Reinstall the collet/flat spring assembly a.
2.
3.
4.
5.
6.
7.
8.
Reinstall the collet actuator roll II and the
pressure roll II .
Turn the collet acutator rod 1m down against the
flat spring.
Reinstall
the diskette locking lever II in the open
position.
Reinstall
the screw and the nut iBJ. Leave the
screw loose.
Push the diskette locking lever toward the collet
actuator rod until there is a maximum gap fJ of
0.1 millimeter (0.004 inch) between the diskette
locking lever and the diskette guide fJ. Tighten
the screw iBJ.
Reinstall the bail II!] on the collet actuator rod 1m.
Ensure that the bail return spring m is in the correct
position. Place the bail ml under the head load arm
D. Install the pivot rod Dand tighten screw g.
Close the diskette locking lever IJ .
9. Push the bail inward slightly and reconnect the bail
actuator cable eyelet lito the bail lever 1m.
Ensure that the crimp on the eyelet faces out.
10. If the bail actuator cable is twisted, turn the solenoid
plunger
iD.
11. Open the diskette locking lever IJ .
12. (51TD) Remove the paper from between the heads,
or remove the scratch diskette.
13. Insert and remove a diskette. The diskette should
move into and out of the diskette drive smoothly
without hitting the collet. If it does not, install a
new flat spring.
14. Perform
the head gap adjustment (see 345).