HCD-GRX5, HCD-RX66, MHC-GRX5, MHC-RX66 - Sony Audio Service Manual (repair manual). Page 16

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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 10 M

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 test point TP (FEO).
2. Connect between test point TP (FOK) and GND by lead wire.
3. Turn Power switch on.
4. Put disc (YEDS-18) in and turned Power switch on again and

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

5. Check 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 and playback.
4. Confirm that oscilloscope waveform is clear and check RF

signal level is correct or not.

Clear RF signal waveform means that the shape “≈” can be clearly
distinguished at the center of the waveform.

+
–

BD board

TP (FEO)
TP (VC)

oscilloscope

A

B

symmetry

within 3 

±

 1 Vp-p

+
–

BD board

TP (RF)
TP (VC)

oscilloscope

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

level:
1.3 

±

 0.3 Vp-p

Procedure:
1. Connect oscilloscope to test point TP (TEO) on BD board.
2. Turned Power switch on. Press 

[FUNCTION]

 button to select

CD.

3. Put disc (YEDS-18) in to play the number five track.
4. Press the

p

button, 

[ENTER/NEXT]

 button and 

^ but-

ton simultaneously several times to fluorescent indicator tube
display “SHUFFLE” is blink. (The sledding servo is turned
OFF.)

5. Check the level B of the oscilloscope’s waveform and the A

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

Traverse waveform

6. Press the

p

button, 

[ENTER/NEXT]

 button and

^ button

simultaneously several times to fluorescent indicator tube dis-
play “SHUFFLE” is OFF. (The sleding servo is turned ON.)
Confirm the C (DC voltage) is almost equal to the A (DC volt-
age) is step 5.

Traverse waveform

+
–

BD board

TP (TEO)
TP (VC)

oscilloscope

A (DC 

voltage)

B

0 V

level: 500 

±

 100 mVp-p

symmetry

Center of the waveform

C (DC 

voltage)

0 V

Sled servo ON

Sled servo OFF

A

×

 100 = less than ±7 (%)

B