CMT-C5, HCD-C5 - Sony Audio Service Manual (repair manual). Page 33

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1. CD Block is basically designed to operate without adjustment. There-

fore, 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 following checks.

As the laser diode in the optical pick-up (OPTIMA-720L1E) is easily
damaged by static electricity, solder the laser tap of the flexible
board when handling it. Before disconnecting the connector, solder
first. Before connecting the connector, be careful not to remove the
solder. Also take adequate measures to prevent damage by static
electricity. Handle the flexible board with care as it breaks easily.

Procedure:
1. Connect an oscilloscope to test point TP (RFAC) and TP (DVC

1.65V) on the BD (CD) board.

2. Turn the power on.
3. Put the disc (YEDS-18) in to playback the number five track.
4. Confirm that oscilloscope waveform is clear and check RF sig-

nal level is correct or not.

A clear RF signal waveform means that the shape “

◊

” can be clearly

distinguished at the center of the waveform.

                    RF signal waveform

Checking Location: BD (CD) board

+

–

BD (CD) board

TP (RFAC)

TP (DVC 1.65V)

oscilloscope

(AC range)

VOLT/DIV: 200 mV

TIME/DIV: 500 ns

level: 1.1 

±

0.3 Vp-p

pick-up

frexible board

laser tap

– BD (CD) BOARD –

TP 

(RFAC)

TP

(DVC 1.65V)

IC103

IC101