Table of Contents
Advertisement
5.8.6
INDEX/SECTOR TIMING ADJUSTMENT
To adjust index/sector timing, see Figure 5-4 and use the following procedure:
A.
Insert an Alignment Diskette.
B.
Start motor and select disk drive.
C.
Sync oscilloscope with external positive probe on TP5 to monitor +Index
signal, then set time base on oscilloscope to 50 microseconds/division.
D.
Connect probe to TP1 and TP2 and ground probes.
On oscilloscope, set inputs to AC and set vertical deflection to
500 millivolts/division.
E.
Step to track .1;31.
F.
Observe timing between start of sweep and first data pulse. This should
be 200
±.
100 microseconds. If timing is not within tolerance, continue
with adjustment.
G.
Loosen mounting screw in appropriate Index Sensor block until
assembly is just able to be moved. This is located on bottom of disk drive.
H.
Observe timing and adjust Index Sensor position until timing is 200
±.
50 microseconds. Verify that detector assembly is against registration
surface.
I.
Open and close door; then, recheck timing. Repeat several times.
J.
Tighten mounting screw slowly. Do not overtighten.
K.
Recheck timing to ensure Index Sensor did not move when mounting
screw was tightened.
INDEX SENSOR
MOUNTING SCREW
Figure 5-4. Index/Sector Timing Adjustment
5-16
Advertisement
Table of Contents
