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— 13 —
CD SECTION
Note:
1. CD Block is basically constructed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M
Ω
impedance.
4. Clean the object lens by an applicator with neutral detergent
when the signal level is low than specified value with the fol-
lowing checks.
5. Adjust the focus bias adjustment when optical block is replaced.
Focus Bias Adjustment
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
FEO
VC
–
+
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
CD DECODER
board
CN12
DC voltmeter
R07
VR01
Focus Bias
Focus Gain
VR02
Focus Gain Adjustment (VR02)
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.
Adjustment Location
[CD DECODER BOARD] — Component side —
CN12
IC03
RF Level
IC01
FEO
VC
Summary of Contents for HCD-G101
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