PMC-DR45L - Sony Audio Service Manual (repair manual). Page 21

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This check is to be done when the optical pick-up block is replaced.

Check Procedure:
1. Connect the oscilloscope to test point TP (VC) and TP (TE) on

MAIN board. Insert disk (YEDS-18).

2. Put the set into test mode.
3. Optical pick-up setting to the center by > or . button

pushing.

4. Press u button.
5. Check that the oscilloscope traverse waveform is symmetrical,

as shown in the figure below.

6. Release test mode after adjustment is completed.

1. Perform the traverse check in the CD test mode.

After check, be sure to exit the test mode.

2. Perform check in the order given.
3. Use the disc (YEDS-18, Parts No. 3-702-101-01) only when so

indicated.

Put the set into test mode and perform the following checks.
Repair if there are any problems.

Press >, . keys and confirm that the Optical pick-up moves
smoothly from the innermost to outermost circumference and back
smoothly and with no catching or abnormal noises.
(Cancellation of BTL mute)
> : Optical pick-up moves to the outer circumference.
. : Optical pick-up moves to the inner circumference.

1. Press the CD u key. (Focus search operation is performed

continuously.)

2. Look at the Optical pick-up objective lens and confirm that it

moves up and down smoothly, with no catching or abnormal
noises.

3. Press x button.

Confirm that focus search operation stops. If it does not, press
x button again longer.

1. Turn the power on.
2. Solder the TEST-C pattern on the TOP board to short.

1. Turn the power off and remove the solder.
2. Turn the power on again.

This check is to be done when the optical block replaced.

Check Procedure:
1. Connect the oscilloscope to test point TP (VC) and TP (RF) on

MAIN board. Insert disk (YEDS-18).

2. Put the set into test mode.
3. Optical pick-up setting to the center by + or – button pushing.
4. Press the u button and press the DISPLAY ENTER button.

(Tracking servo ON)

5. Check that the oscilloscope waveform is as shown in the figure

below (eye pattern).
A good eye pattern means that the diamond shape (    ) in the
center of the waveform can be clearly distinguished.

6. Release test mode after adjustment is completed.

• RF signal reference waveform (eye pattern)

When observing the eye pattern, set the oscilloscope for AC range
and raise vertical sensitivity.