Radio Shack TRS-80 Service Manual page 118

HEAD AMPLITUDE/COMPLIANCE CHECK
1. Insert a blank diskette and write a pattern to
track 34.
2. Set Scope:
Time Base to 10.usec/div.
Read the amplitude.
3. Apply an additional 15 grams of pressure to the
head load arm. (15 grams is approximately equal
to the weight of a 25 cent peice.
4. Observe the amplitude. If it increases more than
10%, the compliance needs to be adjusted.
5. To adjust the compliance, loosen the two nuts
that hold the head load arm in place. While mon-
itoring the amplitude, move the arm until output
is highest. Hold the arm in this position and tight·
en the nuts.
6. Re-verify compliance. If compliance cannot be
adjusted properly, replace the head load arm.
UPPER ARM
"::;§
FINAL CHECK
1. Use the drive to format and backup a blank disk·
ette.
2. Check the diskette in a known good drive.
-=~=---CARRIAGE
~ NUTS
FIGURE 16. UPPER ARM AND CARRIAGE
111