CDP-SP55, CMT-SP55MD, CMT-SP55TC - Sony Audio Service Manual (repair manual). Page 11

11

Note :

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. Connect oscilloscope to TP (FEO).
2. Connect between TP (FEI) and TP (VC) by lead wire.
3. Connect between TP (AGCCON) and TP (DGND) by lead wire.
4. Press the  "/1  button (TA).
5. Load a disc (YEDS-18) and actuate the focus search. (In

consequence of open and close the disc tray, actuate the focus
search)

6. Confirm that the oscilloscope waveform (S-curve) is

symmetrical between A and B. And confirm peak to peak level
within 4 ±1 Vp-p.

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

brightness to obtain best waveform.

Procedure :
1. Connect oscilloscope to TP (RF).
2. Connect between TP (AGCCON) and TP (DGND) by lead wire.
3. Press the  "/1  button (TA).
4. Load a disc (YEDS-18) and playback.
5. Confirm that oscilloscope waveform is clear and check RF signal

level is correct or not.

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

±

Clear RF signal waveform means that the shape “

◊” can be

clearly distinguished at the center of the waveform.

RF signal waveform

Procedure:
1. Connect oscilloscope to TP (TEO) and TP (VC) board.
2. Press the  "/1  button (TA).
3. Load a disc (YEDS-18) and playback the number five track.
4. Press the  H  button. (Becomes the 1track jump mode.)
5. Confirm that the level B and A (DC voltage) on the oscilloscope

waveform.

1 track jump waveform

Specification level:      

x

 100=less than ±22%

6. After check, remove the lead wire connected in step 1.

Procedure :
1. Connect frequency counter to test point (XPCK) with lead wire.

2. Press the  "/1  button (TA).
3. Put the disc (YEDS-18) in to play the number five track.

Confirm that reading on frequency counter is 4.3218MHz.

±

±

A
B