Tandon TM100-1 Operating And Service Manual page 51

4 . Tum the cam screw until the Cats Eye
patterns are equal in amplitude (Figure
5-6).
5 . Tighten the module retaining screws
with a 7/64-inch Allen wrench.
6 . Recheck the Radial Track alignment
5.7 INDEX CH ECK S AND
ADJUSTMENT
The index adjustment changes the time period
from the index pulse to the start of the data in
hard sectored diskettes. The adjustment should
be checked after the drive has been aligned or
when diskette interchange errors are suspected.
If the index checks and adjustments fail, refer
to the troubleshooting guide.
INDEX-TO-DATA PULSE CH ECK S
1 . Set up the oscilloscope:
Channel A: Test Point 1
Channel B: Test Point 2
Ground: Test Point 6
Read Differentially: A plus B, B inverted
Time Base: 50 microseconds per division
External Trigger: Test Point 7 , negative
Adjust amplitude for at least two divi­
sions on the oscilloscope.
2 . Apply power to the drive.
3 . Select the drive with the control logic.
4. Check the speed of the drive' s motor.
5 . Insert an alignment diskette.
6 . Seek the carriage to Track 1 .
edge
7 . Select Head 0 .
8 . Read the trigger point to the start of the
first data pulse width (Figure 5-8).
9. For double-sided drives, if Head 0 , the
lower head, meets the tolerance, check
the upper head.
Head 1 should meet the same
tolerance.
10. If either head does not meet the
tolerance, adjust the index sensor.
1 1 . Recheck both indexes after they are
adjusted.
12. When both index measurements on a
double-sided drive or the one index mea­
surement on a single-sided drive meet
the tolerance, check the index on Track
34.
13. For double-sided drives, check Heads 0
and 1 .
If any index measurement does
not meet the tolerance, the index
sensor must be adjusted.
14. R ech eck
adjustment.
INDEX SEN SO R ADJUSTMENT
1 . From the bottom of the chassis, loosen
the index sensor' s retaining screw coun­
terclockwise one-quarter turn (Figure
5-9).
2. Adjust the index sensor with a flat blade
screwdriver until the data pulse begins
200 microseconds ± 100 microseconds
from the trigger point.
3 . Tighten the index sensor' s retaining
screw.
4 . Recheck the index-to-data pulse.
5-9
NOTE
NOTE
all in dexes a fter each