CDP-CX260 - Sony Audio Service Manual (repair manual). Page 21

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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

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.

Procedure :
1. Chuck the disc (YEDS-18) beforehand, and disconnect the power

cord from the outlet.

2. Connect oscilloscope to test point TP (FE1) on BD board.
3. Connect test point TP1 (ADJ) on MAIN board to ground with

lead wire.

4. The ADJ mode is set when the power cord is inserted into the

outlet and power is supplied.

5. The fifth track is played automatically.
6. Press the  CHECK  button.
7. Check the oscilloscope waveform (S-curve) is symmetrical be-

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

S-curve waveform

8. Pressing the  p  button stops the output of the waveform (s curve).
9. After check, remove the lead wire connected in step 3.
Note : • 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 bright-

ness to obtain best waveform.

Note: A clear RF signal waveform means that the shape “

◊

” can be

clearly distinguished at the center of the waveform.

RF signal waveform

Procedure :
1. Chuck the disc (YEDS-18) beforehand, and disconnect the power

cord from the outlet.

2. Connect oscilloscpe to test point TP (TE) on BD board.
3. Connect test point TP1 (ADJ) on MAIN board to ground with

lead wire.

4. The ADJ mode is set when the power cord is inserted into the

outlet and power is supplied.

5. The fifth track is played automatically.
6. Press the  GROUP 3  button. (The tracking servo and the sled-

ding servo are turned OFF.)

7. 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 x 100 = less than ± 22%

Traverse waveform

8. Press the  GROUP 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 7.

Traverse waveform

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

level is correct or not.

9. Disconnect the lead wire of TP1 (ADJ) connected in step 2.

oscilloscope

BD board

TP (FE1)
TP (VC)

symmetry

A

B

Within 3 

±

 1 Vp-p

oscilloscope

BD board

TP (RF)
TP (VC)

VOLT/DIV : 200mV
TIME/DIV : 500ns

level : 1.2         Vp-p

+0.25
–0.20

oscilloscope

BD board

TP (TE)
TP (VC)

0V

level : 1.3 

±

 0.6 mVp-p

A (DC voltage)

Center of the waveform

B

0V

C (DC 
voltage)

Tracking servo
Sledding servo
        OFF

Tracking servo
Sledding servo
        ON