MHC-VX888 (serv.man2) - Sony Audio Service Manual (repair manual). Page 16

16

On this mode, the data of the color-bars signal as a picture signal
and the 1 kHz sine wave signal as a sound signal are output by the
mechanism controller (IC502) for the video CD signal check.  When
measurement of the voltage and waveform on the VIDEO board,
perform it in this mode.
For reference, the color-bars signal can be observed at CN301 pin
2

  using an oscilloscope.

Procedure:
1. Short the both ends of the land of SL503 of the VIDEO board.
2. Turn the power on. Press the  CD  button to select CD.
3. The color-bars appears when the CD is in stop status, and it

disappears when the CD goes in play status.

4. After measuring, remove the lead wire connected.VIDEO board

(SIDE B)

Procedure:
1.

Short SL502 on the VIDEO board by soldering.

2.

Turn on the main power.  Set a disc on the DISC1 tray.  Select
CD.

3.

Press the hH button to play back CD.

4.

When the  > +  button is pressed, 100 track jump is executed.

5.

Also, every pressing of the PLAY MODE button triggers
between  ON and OFF of TRACKING SERVO and SLED
SERVO.

How to quit the CD servo ON/OFF mode:
1.

Press the  ?/1  button to turn off the main power.

2.

Remove soldering from SL502.