ICF-CD873L - Sony Audio Service Manual (repair manual). Page 9

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Note:
Tracking Balance Adjustment and Tracking Gain Adjustment are
done automatically in this set.

1. Press the CD LID OPEN/CLOSE DET switch (S424) on the

PUSH SWITCH board.

2. Under standby condition (when the clock appears in the dis-

play), short the BP (CD TEST AUTO).

 If the power is supplied to the microprocessor once, it is backed up

for 3 minutes, therefore the TEST mode will not be activated within
3 minutes even if the power is turned on again. In this case, short
instantaneously the BP (CD TEST MANUAL).

3. Press the  fl key, and the focus search is repeated.

At this time, check that the optical pick-up objective lens moves
smoothly without a sticking or noise.

4. Load the test disc (YEDS-18: Part No. 3-702-101-01), and per-

form automatic adjustment after the focus search succeeded.

5. After automatic adjustment is finished, move the sled motor

to the center. At this time, keep pressing the + and =
keys to confirm that optical pick-up moves smoothly via most
inside track 

→

 most outside track 

→

 most inside track with-

out a sticking or noise.

6. Confirm the traverse waveform.
7. Press the [WAKE UP TRACK] key.
8. The tracking servo and the sled servo are turned on, the mute

is cancelled.

9. Playback the 2nd track.
10. Adjust the RF and jitter waveforms.

Connecting points: MAIN Board (See page 12)

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

Adjustment Procedure:
1. Connect the oscilloscope to TP504 (VREF) and TP503 (RF)

on the MAIN board.

2. Insert the test disc (YEDS-18: Part No.3-702-101-01) and press

fl key to play.

3. Move the optical pick-up to the music area on the disc to en-

able easy visibility of the eye pattern by + or = key
pressing.

4. Adjust RV501 so 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.

Adjustment Location: MAIN Board (See page 12)

MAIN board

TP503 (RF)

TP504 (VREF)

+
–

oscilloscope

(AC range)

VOLT/DIV: 0.2 V
TIME/DIV: 500 ns

1.3 

±

 0.5 Vp-p

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