— 13 —
CD SECTION
Focus Bias Adjustment
FEO
VC
DC voltmeter
–
+
RF Level Check
Procedure :
1. Connect oscilloscope to test point TP (RF) on CD DECODER
board.
2. Turned Power switch on.
3. Put disc (YEDS-18) in and playback.
4. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
Note: Clear RF signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.
TP (RF)
CN12 (VC)
CD DECODER
board
oscilloscope
level: 1.0 Vp-p
VOLT/DIV: 200 mV
TIME/DIV: 500 nS
+0.3
–0.2
Adjustment Location
[CD DECODER BOARD] — Component side —
Adjustment Location: CD DECODER board
This gain has a margin, so even if it is slightly off.
There is no problem.
Therfore, do not perform this adjusment.
Please note that it should be fixed to mechanical center position
when you moved and do not know original position.
Procedure:
1. Connect DC voltmeter to test point CN12 (FEO), (VC) on CD
DECODER board.
2. Turned Power switch on.
3. Put disc (YEDS-18) in and stop.
4. Adjust VR01 so that the DC voitmeter reading is 0 ± 20 mV.
Adjustment Location: CD DECODER board
R07
CN12
IC03
VR01
Focus Bias
RF Level
IC01
FEO
VC
CD DECODER
board
CN12
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