Pioneer PDR-W839 Service Manual page 75

6.8.13 Focus Bias Adjustment
Test Point
Adjustment Value
Purpose
Symptom when Out of Adjustment
[Procedure]
1. Move the Pickup to center of the disc by pressing the SCAN key. (
2. Monitor the jitter value and set a CD disc. (use the jitter meter)
3. Press the FINALIZE key to FOCUS IN.
4. Press the PLAY/PAUSE key to turn the SPINDLE. (CAV)
5. Press the PLAY/PAUSE key to TRACKING ON. (EFM CLV)
6. Adjust the JOG key so that jitter value becomes minimum.
7. Press the ENTER key to register the adjustment.
\ Shift to the RFDC Level Adjustment automatically.
8. Adjustment is completed automatically.
\ Each display the reason that became abnormal when adjustment was not completed normally.
When did not converge in limit of adjustment possibility
(when it became the lowest level)
When failed in writing to the EEPROM
9. Press the STOP key to stop the operation.
Caution:
In this adjustment, shift to the RFDC Adjustment when pressing the ENTER key before step 7, and there is
it when completed in normal on the indication.
However, must not omit operation of steps 5 from 3 because RFDC is not adjusted to normal when
pressing the ENTER key with the state that steps 5 from 3 are not executed.
CN102
2
RF
10: 1 prove
6
VC
How to execute the automatic adjustment once again after the automatic adjustment is completed:
1. Press the STOP key to stop the disc rotation. (servo OFF)
2. Press the AUTO SPACE key and shift to the Focus Offset adjustment.
3. Press the REC/REC MUTE key to start the automatic adjustment.
Adjust from "6.8.11 automatic Adjustment Start" to "6.8.13 Focus Bias Adjustment".
Press the STOP key when stops execution of the automatic adjustment on the way and stop processing. Then return to the state of
"6.8.10 Preparations" and stop the operation.
CN102-pin 2 (RF)
Minimize jitter value
Optimizing DC offset voltage of focus servo loop circuit including pickup.
Focus-in does not function, sound pauses, bad RF wave form, or incapable of
playing some discs.
Adjustment method
Oscilloscope
41 ¡¢ )
PDR-W839
FL Indication
75