Casio ZD-1 Service Manual page 15

Focus Servo Gain Adjustment (Figures 9 and 11)
Step Connect
1 See Play the regular disc.
Figure 9
Oscilloscope
Tracking Servo Adjustment (Figures 10 and 11)
Step Connect
1 See Play the regular disc.
Figure 10
Swap the regular disc for the test disc A*BEX TCD-726 and play it at the black dod of 600 µm.
2
Confirm that there is no skipping.
3 If there is any skipping, adjust VR 703 to reduce the tracking servo gain until no skipping occurs.
Oscilloscope
Setting Adjust
VR704
GND
Figure 9
Setting Adjust
VR703
GND
Figure 10
13
Result
CD PCB
TP750
TP710
Result
CD PCB
TP751
TP710
0V 250 mV p-p
0V 100 mV p-p