Shugart SA800 User manual

SASOO/SOl ~
Diskette Storage Drive ~[]
~
@
2)
@!J
2)
©
@
~
@!J
2)
~
@!J
C==J
. ~®ShUgart Associates

SA800/801 ~
Diskette Storage Drive ~[]
~
@
2)
@!J
2)
©
@
~
@)
2)
~
@)
C==J
© Copyright 1977 Shugart Associates

TABLE OF CONTENTS
Section
Maintenance Features
Page
2
3
4
5
6
7
8
9
Diagnostic Techniques
Preventive Maintenance.
Removals Adjustments .
Physical Locations . .
SAS09Exerciser Connections
SASOO/SOl PCB Component Locations
SASOO/SOl L.ogic Manual. . .
SASOO/SOl Schematic Diagrams
3
5
7
17
21
22
23
31

1.0 MAINTENANCE FEATURES
1.1 Alignment Diskette
The SA 120 Alignment Diskette is used for align-
ment of the SA800/80I. The following adjust-
ments can be made using the SA120.
1. RjW Head radial alignment using track 38.
2. R/W Head azimuth alignment using track 76.
3.
Index Photo-Detector Adjustment using tracks
01 and 76.
4. Track
00 is recorded with standard IBM 3740
format.
5.
TK 75 has 1f + 2f signal for load pad adjustment.
Caution should be exercised in using the
SA 120
Alignment Diskette. Tracks
00, 01, 36, 37,38,39,
40, 75, and 76 should not be written on. To do so
will destroy pre-recorded tracks.
1.2 SA809 Exerciser
The SA809 Exerciser is built on aPCB whose
dimensions are
8" x 8". The Exerciser PCB can be
used in astand alone mode or it can be built into
atest station
or used in atester for field service.
The Exerciser
is designed to enable the user to
make all adjustments and check
outs required on
the SA800/80 1drives, when used with the SA 120
alignment diskette.
The exerciser has
no intelligent data handling
capabilities
but can write both 1fand 2f frequen-
cies. The exerciser can enable read in the drive to
allow checking
of read back signals.
Refer
to Section 6for illustration.
1.3 Special Tools
The following special tools are available for
performing maintenance on the SA800/80
I.
Description
AlignmentDiskette
Cartridge Guide Adj. Tool
Head Penetration Gauge
Load
Bail Gauge
Exerciser
Spanner Wrench
Part
Numher
SA120-1
50377-1
50380-0
50391-0
SOC) 19-0
50752-0

3
2.0 DIAGNOSTIC TECHNIOUES
2.1 Introduction
Incorrect operating procedures, faulty program-
ming, damaged diskettes, and "soft errors" created
by airborne contaminants, random electrical noise,
and other external causes can produce errors
falsely attributed to drive failure or misadjustment.
Unless visual inspection of the drive discloses an
obvious misalignment or broken part, attempt to
repeat the fault with the original diskette, then
attempt to duplicate fault on second diskette.
2.2 "Soft Error" Detection and Correction
Soft errors are usually caused by:
1. Airborne contaminants that pass between the
read/write head and the disk. Usually these
contaminants can be removed by the cartridge
self-cleaning wiper.
2. Random electrical noise that usually lasts for a
few 11 sec.
3. Small defects in the written data and/or track
not detected during the write operation that
may cause asoft error during aread.
4. Worn or defective load pad.
The following procedures are recommended to
recover from the above mentioned soft errors:
I. Reread the track ten (10) times or until such
time as the data is recovered.
2. If data is not recovered after using step] ,access
the head to the adjacent track in the same
direction previously moved, then return to the
desired track.
3. Repeat step 1.
4. If data is not recovered, the error is not
recoverable.
2.3 Write Error
If an error occurs during awrite operation, it will
be detected on the next revolution by doing aread
operation, commonly called a "write check." To
correct the error, another write and write check
operation must be done. If the write operation is
not successful after ten (10) attempts have been
made, aread operation should be attempted on
another track to determine if the media or the
drive is failing. If the error still persists the diskette

2.6 Test Points·· 800/801
should be replaced and the above procedure
repeated. If the failure still exists, consider the
drive defective. If the failure disappears, consider
the original diskette defective and discard it.
2.4 !Read Error
Most errors that occur will be "soft" errors.
In these cases, performing an error recovery
procedure will recover the data.
2.5 Seek Error
I. Stepper malfunction.
2. Improper carriage torque.
To recover from aseek error recalibratc to track
00 and perform another seek
to the original track.
TP
2
3
4
5
6
7
10
II
12
16
21
24
25
26
27
Read Data Signal
Read
Da ta Signal
Read Data (Differentiated)
Read Data (Differentiated)!
Signal Ground
Signal Ground
Signal Ground
-Index
+Head Load
-Index and 80 ISector Pulses
+Read Data
-Data Separator Time +I
-Data Separator Time +2
+Write Protect
+Detect Track 00.
+Gated Step Pulses
2.7 Test Point Locations
1 • •
••
J5
10
••
11
0
7J2
P2
025
26 0
012 A
20
P1
J1
•
~
J6.
27 •
49
0
V
21
10
0 0 16
0
0
24
21
0010
~
0
6
J3i
04350
000P3
4

3.0 PREVENTIVE MAINTENANCE
3.1 Introduction
The prime objective of any preventive maintenance
activity
is to provide maximum machine avail-
ability to the user. Every preventive maintenance
operation should assist
in realizing this objective.
Unless apreventive maintenance operation cuts
machine downtime, it
is unnecessary.
Visual inspection
is the first step in every sched-
uled maintenance operation. Always
look for
corrosion, dirt, wear, binds, and loose connections.
Noticing these items during
PM may save down-
time later.
Remember, do
not do more than recommended
preventive maintenance on
equipment that is
operating satisfactorily.
3.2 Preventive Maintenance Procedures
Details of preventive maintenance operations are
listed in Figure
1. During normal preventive
maintenance,
perform only those operations listed
on the
chart for that preventive maintenance
period. Details on adjustments
and service checks
can be found in the maintenance manual. Observe
all safety procedures.
3.3 Cleanliness
Cleanliness cannot be overemphasized in maintain-
ing the SA800/80
1. Do not lubricate the SA800/
801; oil will allow dust and dirt to accumulate.
The read/write head should be cleaned only when
signs
of oxide build up are present.
uns
ment
reas
ws,
es
FREQ
UNIT
MONTHS CLEAN
OBSERVE
Read/Write Head
12 Clean Read/Write Head Oxide build up
ONLY IF NECESSARY
R/W Head Load
12* Replace
Button
Stepper Motor and
12
Clean off all oil, dust, Inspect for nicks and b
Lead Screw
12
and dirt
Belt
12
Frayed or weakened a
Base
12 Clean base Inspect for loose scre
connectors, and switch
Read/Write Head
12
Check for proper align
*Assumes normal usage Figure 1PM Procedures
5