Pioneer PD-117 Service Manual page 28

1
A
9. Focus Best Adjustment
Test mode
SPDL servo
FOCUS servo
TRKG servo
TEST DISC
PLAY
B
START
C
MOTHER BOARD ASSY
10. Focus Servo Loop Gain Adjustment
Test mode
SPDL servo
D
FOCUS servo
TRKG servo
TEST DISC
E START
FE
FI
VC
MOTHER BOARD ASSY
F
28
1
2
=
CLOSE
=
CLOSE
=
CLOSE
Innermost
circumference
(1 TRK)
MOTHER BOARD ASSY
Player
TP1
(CN201)
6
FE
1
RF
4
VC
=
CLOSE
=
CLOSE
=
CLOSE
Innermost
circumference
(1 TRK)
PLAY
MOTHER BOARD ASSY
Player
TP1
(CN201)
6
5
100kΩ
4
2
3
VR156
Adjust the RF level to maximum, with
the focus error voltage within ±150mV.
Prove (10:1)
Prove (10:1)
UNDER
VR152
Readjust if
adjustment
is incorrect.
Prove (10:1)
Prove (10:1)
56kΩ
0.001µF
Low pass filter 2
PD-217
3
4
MAX
Oscilloscope
DC Mode
CH1: 5mV/div
CH2: 20mV/div
H: 200ns/div
Check
UPPER
JUST
Lissajous Waveform
Oscilloscope
X-Y Mode
X: 20mV/div
Y: 5mV/div
Low-frequency
oscillator
1.2kHz
1Vp-p
GND
4