Sony MVC-CD300 Service Manual page 69

7-3-4. Focus Gain, Tracking Gain
Purpose:
Perform this adjustment to minimize the variations in the focus gain
and the tracking gain caused by the OP (optical device).
Trouble Symptom
NG is displayed.
Cause of Trouble
As the result of adjustment, variation has exceeded the
specification value.
Remedial Measure
Replace the OP (optical device).
7-3-5. Focus Bias RF
Purpose:
Perform this adjustment to minimize the variations of the focus fine
gain to the CD caused by the OP (optical device) and IC.
Trouble Symptom
No symptom is displayed. (The OK message always appears because
OK/NG judgment is not performed.)
7-3-6. MPP Out Adjust
Note: MPP = Main Push Pull
Purpose:
Perform this adjustment to minimize the variations of MPP offset
to the CD caused by the OP (optical device) and IC.
Cause of Trouble
As the result of adjustment, variation has exceeded the
specification value.
Remedial Measure
Replace the OP (optical device).
7-3-7. RF Gain
Purpose:
Adjust the gain of OP (optical device) for the CD.
Trouble Symptom
No symptom is displayed. (The OK message always appears because
OK/NG judgment is not performed.)
7-3-8. RF Jitter Check
Purpose:
Check the variation of jitter caused by OP (optical device) when the
CD is played back.
Trouble Symptom
The measured value of the jitter has exceeded the allowable range
of specifications. (Jitter is 8 ns or less.)
Cause of Trouble
• When the trouble occurs after the OP is replaced.
The SKEW adjustment is incomplete.
• When the trouble is found during troubleshooting.
The actuator of the OP is deformed by dropping the machine
or others.
Remedial Measure
Repeat the SKEW adjustment and the subsequent adjustments.
If the trouble is not remedied even the SKEW adjustment is
performed, execute the Self RF Jitter Check of the Write (CDR)
Adjustment. If the adjustment ends with success, the trouble is
remedied.
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