HCD-G1, LBT-G1, LBT-G1R, LBT-G1S - Sony Audio Service Manual (repair manual). Page 13

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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.

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

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.

MAIN Board

DISC LED board

PANEL board

SENSOR board

TUNER board

SW (D) board

SW (C) board

MOTOR (6P) (S) board

MOTOR board

SW (B) board

O/C board

CD DECODER board

R/P SWITCH board

SW (A) board

AC SUPPLY board
(E, Argentine, Mexican)
AC POWER SUPPLY board (AEP, UK)

VOL SELECT board (E, Argentine)

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RF Level

Focus Gain

CN12

IC03

IC01

FEO

VC

VR01

VR02

R07

Focus Bias