Track Follower Alignment - HP 7925D Service Manual

Alignment and Adjustment
7925
®
Clockwise - causes the values to shift in a positive direction
®
Counterclockwise - causes the values to shift in·a negative direction
7311-81
Figure 3-16. Track Follower Alignment
a. Perform the warmup procedure outlined in paragraph
3-13.
b. On the DSU, set the FUNCTION switch to position 7.
Note: Do not stop the spindle while the DSU
is set to FUNCTION 7. If the spindle
must be stopped, remove any tools from
the actuator assembly; set the DSU to
FUNCTION 1; press the START push-
button, then the STOP pushbutton; and
then set the RUN/STOP switch to
STOP.
c. Tighten the servo head to 5 inch-pounds.
3-18
d. On the DSU, set the FUNCTION switch to position 1
(ALTERNATE SEEK).
e. On the DSU, select cylinder address 822 on the upper
bank often switches (switches 512, 256, 32, 16,4, and
2 set to the right).
f. On the DSU, select cylinder address 896 (illegal ad-
dress) on the lower bank of switches (switches 512,
256, and 128 set to the right).
g. Press the START pushbutton on the DSU. The heads
will go to cylinder 822 and remain at 822.