Pioneer PD-F958 Service Manual page 34

PD-F958, PD-F908
9. Focus Best Adjustment
Test mode
=
SPDL servo
=
FOCUS servo
=
TRKG servo
Innermost
TEST DISC
circumference
(1 TRK)
PLAY
START
(CN201)
FE
RF
VC
MAIN BOARD ASSY
10. Focus Servo Loop Gain Adjustment
Test mode
SPDL servo
FOCUS servo
TRKG servo
Innermost
TEST DISC
circumference
(1 TRK)
PLAY
START
TP1
(CN201)
6
FE
5
FI
4
VC
MAIN BOARD ASSY
34
CLOSE
CLOSE
CLOSE
MAIN BOARD ASSY
Player
TP1
6
1
4
=
CLOSE
=
CLOSE
=
CLOSE
MAIN BOARD ASSY
Player
100kΩ
Low pass filter 2
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
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