HCD-GS100 - Sony Audio Service Manual (repair manual). Page 22

22

Procedure:
1.

Connect an oscilloscpe to test point TP (TE) and TP (DVC) on
the CD board.

2.

Turn the power on.

3.

Select the function “CD”.

4.

Press three buttons of 

[ENTER]

,

M

, and 

[REPEAT]

 si-

multaneously to set the CD service mode.

5.

Put the disc (YEDS-18) in to playback the number five track.

6.

Press the  

.

  button.  (The tracking servo and the sledding

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  

.

  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 5.

9. To exit from this mode, perform as follows.

1) Move the optical pick-up to the most inside track.
2) Press three buttons of

x

, 

[CLEAR]

, and 

[DISPLAY]

simultaneously. (cold reset)

• Always move the optical pick-up to most inside track when

exiting from this mode. Otherwise, a disc will not be unloaded.

• Do not run the sled motor excessively, otherwise the gear can

be chipped.

Traverse Waveform

Checking Location: CD board (Conductor side)

+
–

CD board

TP (TE)

TP (DVC)

oscilloscope

0V

B

level: 1.15 

±

 0.5 Vp-p

Center of 
the waveform

A (DC 

voltage)

0V

Tracking servo

Sled servo

ON

C (DC 
voltage)

Tracking servo

Sled servo

OFF

TP (VC)

TP (FE)

TP (TE)

TP

 (RFDC)

TP

 (DVC)

TP

 (RFAC)

IC103

IC101