Skew Adjustment; Dvd Core Unit - Pioneer AVH-P5200BT Service Manual

1

-SKEW adjustment

The skew adjustment for the pickup is required when the following replacement is performed:
(1) Replacement of the pickup unit
A
(2) Replacement of the spindle motor
(3) Replacement of the carriage chassis
(4) Replacement of the main shaft of the pickup unit
(5) Replacement of the sub-shaft of the pickup unit
• Measuring instrument, jigs and tools: Oscilloscope
• Disc used: GGV1018
• Measurement criterion: AGND2
B
• Measurement point: RF
• Connection diagram

DVD core unit

C
D
E
Symptoms seen in case of inadequate adjustment: Worsened error ratio 10-3 (normally 10-4 or less)
Large RF jitter
RF waveform is distorted
Tracking leading-in/servo is unstable
* Note: Do not directly look at laser beam in adjustment.
F
There are two types of adjustments available: adjustment while monitoring the RF waveform with the oscilloscope
(method 1) and adjustment while checking the RF level values with the OSD (method 2).
The adjustment procedure is shown below. For how to enter the test mode and the operation procedure, see the
sections in the Service Test Mode.
104
1
2
Driver for adjusting SKEW => torques (T2) driver
Bond for fixing SKEW (GEM1033)
Bond for screw lock (GEM1068)
RF
AGND2
Enlarged
AVH-P5200BT/XNUC
2
3
Oscilloscope
3
4
4