Pioneer PD-M427 Servise Manual page 27

9. Focus Best Adjustment
Test mode
=
SPDL servo
CLOSE
=
FOCUS servo CLOSE
=
TRKG servo CLOSE
Innermost
TEST DISC
circumference
(1 TRK)
PLAY
START
TP1
(CN201)
6
FE
1
RF
4
VC
MOTHER BOARD ASSY
10. Focus Servo Loop Gain Adjustment
Test mode
=
SPDL servo
CLOSE
=
FOCUS servo
CLOSE
=
TRKG servo CLOSE
Innermost
TEST DISC
circumference
(1 TRK)
PLAY
START
TP1
(CN201)
6
FE
5
FI
4
VC
MOTHER BOARD ASSY
VR153
MOTHER BOARD ASSY
Player
VR152
MOTHER BOARD ASSY
Readjust if
adjustment
is incorrect.
Player
56kΩ
100kΩ
0.001µF
Low pass filter 2
PD-M427, PD-M407
Adjust the RF level to maximum, with
the focus error voltage within ±150mV.
Oscilloscope
DC Mode
CH1: 5mV/div
CH2: 20mV/div
H: 200ns/div
Prove (10:1)
Prove (10:1)
Check
UNDER
UPPER
JUST
Lissajous Waveform
Oscilloscope
X-Y Mode
X: 20mV/div
Y: 5mV/div
Low-frequency
Prove (10:1)
oscillator
1.2kHz
1Vp-p
Prove (10:1)
GND
MAX
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