Head Azimuth Alignment; Head Assembly Retaining Screws - HP 9130K Service Manual

5-8
Maintenance
Figure 5-5: Head Assembly Retaining Screws
8. After the radial head alignment has been completed, re-tighten the three screws
loosened in step 7 while observing the scope pattern. Tighten the retaining screws
with the torque-driver set at 8 inch pounds.
Head Azimuth Alignment
The head azimuth is not field adjustable due to its very delicate nature. For this reason, the
drive unit should be returned to CSD for azimuth alignment. To determine whether the
head azimuth is out of limits, perform the following procedures:
Connect channel A of the scope to TP4/E4 and ground lead to TPIO/EIL
Connect channel B to TP7/E7 and ground lead to TP6/EIL
Setup the scope as follows:
Trigger: Internal on channel B (pas)
Display: Channel A
Volts/DIV: .02V/DIV
Time/DIV: Ims/DIV
The waveform observed at TP4/E4 should look similar to that of Figure 5-6. Examine the
waveform for heads I and 2. If lobe A is greater in amplitude than lobe B or if lobe D is
greater in amplitude than lobe C, then the head azimuth is out of alignment and thl2 drive
assebly should be returned to CSD for adjustment.