24
1
2
3
4
1
2
3
4
C
D
F
A
B
E
PD-M427
4
2
6
1. Focus Offset Adjustment
Test mode
None disc
VR154
MOTHER BOARD ASSY
DC voltage
0
±
50mV
Oscilloscope
DC Mode
V: 5mV/div
H: 10mSec/div
Prove (10:1)
GND
START
TP1
(CN201)
Player
2. Grating Adjustment
Oscilloscope
DC Mode
V: 10mV/div
H: 5mSec/div
Player
FE
VC
START
TP1
(CN201)
TE
VC
Locate null.
Counterclockwise, Maximum amplitude.
39k
Ω
0.001
µ
F
Prove (10:1)
GND
Low pass filter 1
MOTHER BOARD ASSY
MOTHER BOARD ASSY
6.2.3 Check and Adjustment
4
Test mode
SPDL servo
FOCUS servo
TRKG servo
=
=
=
CLOSE
CLOSE
OPEN
TEST DISC
Innermost
circumference
(1 TRK)
PLAY
Turn counterclockwise
from null.
PICKUP