CDP-C250Z, CDP-C350Z, CDP-C661, CDP-CE305, CDP-CE405 - Sony Audio Service Manual (repair manual). Page 8

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1.

CD Block is basically designed 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  impedance.

4.

Clean the object lens using an applicator with neutral detergent when

the signal level is low than specified value with the following

checks.

Procedure :
1. Connect oscilloscope to test point TP (FE) on BD board.
2. Connect between test point TP (FEI) and TP (VC) by lead

wire.

3. Turn Power switch on.
4. Put disc (YEDS-18) in and turn Power switch on again and

actuate the focus search. (actuate the focus search when disc
table is moving in and out.)

5. Check if the oscilloscope waveform (S-curve) is symmetrical

between A and B. And confirm peak to peak level within 3±1
Vp-p.

S-curve waveform

6. After check, remove the lead wire connected in step 2.

• Try to measure several times to make sure than the ratio of A

: B or B : A is more than 10 : 7.

• Take sweep time as long as possible and light up the

brightness to obtain best waveform.

Procedure :
1. Connect oscilloscope to test point TP (RF) on BD board.
2. Turned Power switch on.
3. Put disc (YEDS-18) in to play the number five track.
4. Confirm that oscilloscope waveform is clear and check if RF

signal level is correct or not.

BD board

TP (FE)
TP (VC)

oscilloscope

symmetry

A

B

within 3 ± 1 Vp-p

BD board

TP (RF)
TP (VC)

oscilloscope

A clear RF signal waveform means that the shape “ 

◊

 ” can be

clearly distinguished at the center of the waveform.

RF signal waveform

Procedure :
1. Connect test point TP (ADJ) to ground with a lead wire.
2. Connect oscilloscpe to test point TP (TE) on BD board.
3. Turned Power switch on.
4. Put disc (YEDS-18) in to play the number five track.
5. Press the “3” button. (The tracking servo and the sledding

servo are turned OFF.)

6. Check the level B of the oscilliscope's waveform and the A

(DC voltage) of the center of the Traverse waveform.
Confirm the following :
A/B 

×

 100 = less than ± 22%

Traverse waveform

7. Press the “8” button. (The tracking servo and sledding servo

are turned ON.) Confirm the C (DC voltage) is almost equal
to the A (DC voltage) is step 6.

Traverse waveform

8. Disconnect the lead wire of TP (ADJ) connected in step 1.

VOLT/DIV : 200mV
TIME/DIV : 500ns

level :

1.2

Vp-p

+0.25

–0.20

BD board

TP (TE)
TP (VC)

oscilloscope

0V

Center of the waveform

B

level : 1.3 ± 0.6 Vp-p

A (DC voltage)

0V

C (DC
voltage)

Tracking servo
Sledding servo

ON

Tracking servo
Sledding servo

OFF