Tandon TM100-1 Operating And Service Manual page 57

5.13 COMPLIANCE CHECK AND
ADJUSTMENT
(SINGLE-SIDED DRIVES)
Compliance is the maximized output of the head
when the pressure of the felt pad is centered
over the read/write gap. For double-sided drives,
a compliance check and adjustment must be
made at the factory. If the compliance check and
adjustment fails, refer to the troubleshooting
guide.
COMPLIANCE CHECK
1 . Remove the screws attaching the logic
circuit board to the guide rails.
2 . Lift out the logic circuit board, and lay it
on the drive.
NOTE
This allows one to reach the drive
to move the head.
3 . Set up the oscilloscope:
Channel A: Test Point 1
Channel B: Test Point 2
Vertical Amplitude: 100 millivolts per
Ground: Test Point 10
Read Differentially : A plus B, B inverted
Time Base: 10 microseconds per division
External Trigger: Test Point 7 , positive
4 . Apply power to the drive.
division
edge
5 . Select the drive.
6 . Insert a nonwrite protected diskette.
7 . Write a IF pattern on Track 34.
8 . Observe the output waveform voltage.
9 . With a gram gauge, carefully apply fif­
teen grams pressure to the upper arm.
Fifteen grams is about the
weight of a quarter.
1 0 . If the output shown on the oscilloscope
increases by more than ten percent,
adjust the compliance.
COMPLIANCE ADJUSTMENT
Compliance is adjusted by using the same proce­
dure used in the compliance check.
1 . Loosen the two screws attaching the
upper arm to the carriage assembly
(Figure 5-14) counterclockwise one-
quarter turn with an Allen wrench.
2 . While monitoring the output, move the
upper arm around the axis of the head
until the output amplitude is highest.
3 . Tighten the two screws, attaching the
upper arm to the carriage assembly,
clockwise with an Allen wrench, while
holding the arm in the highest position.
4 . Reverify the compliance.
5 . If it cannot be adjusted, replace the
upper arm.
5-15
NOTE