Read Sony CFD-Z125 / CFD-Z135 Service Manual online
— 21 —
Focus Bias Adjustment
This adjustment is to be done when the optical pick-up is replaced.
Procedure:
1. Connect the oscilloscope IC701 pin
#¡ and TP701 pin 2 on
the CD DECODER board.
2. Put the disc (YEDS-18.)
3. Put the set into test mode. (See page 20.)
4. Press ± and ≠ buttons to move the optical pick-up to the
3. Put the set into test mode. (See page 20.)
4. Press ± and ≠ buttons to move the optical pick-up to the
center. (Move the optical pick-up to the music area on the disc
to enable easy visibility of the eye pattern.)
to enable easy visibility of the eye pattern.)
5. Press the fl button.
From focus searching, focus is turned ON while entering
CLV drawing-in mode. Tracking and sled are turned OFF.
CLV drawing-in mode. Tracking and sled are turned OFF.
6. Press the fl button.
[Both tracking and sled are turned ON.]
7. Adjust VR701 so that the oscilloscope waveform is as shown in
the figure below. (eye pattern)
A good eye pattern means that the diamond shape (
A good eye pattern means that the diamond shape (
◊
) in the
center of the waveform can be clearly distinguished.
• RF signal reference waveform (eye pattern)
8. Release the test mode after adjustment is completed.
Adjustment Location: CD DECODER board (See page 22.)
E-F Balance Adjustment
This adjustment is to be done when the optical pick-up is replaced.
Procedure:
1.
Connect the oscilloscope to TP702 pin
1 and pin 2 on the
CD DECODER board.
2.
Put the disc (YEDS-18).
3.
Put the set into test mode. (See page 20.)
4.
Press the ± and ≠ buttons to move the optical pick-up to
the center.
the center.
5.
Press the fl button.
From focus searching, focus is turned ON while entering
CLV drawing-in mode. Tracking and sled are turned OFF.
From focus searching, focus is turned ON while entering
CLV drawing-in mode. Tracking and sled are turned OFF.
6.
Adjust VR702 so that the oscilloscope traverse waveform is
symmetrical, as shown in the figure below.
symmetrical, as shown in the figure below.
Adjustment value: 0.3 to 0.7Vp-p (A+B)
7. Release the test mode after adjustment is completed.
Adjustment Location: CD DECODER board (See page 22.)
oscilloscope
(DC range)
CD DECODER board
TP702 pin
1
TP702 pin
2
0V
A
B
A=B
0V
A=B
A
B
VOLT/DIV: 0.2V (with the 10:1 probe in use.)
TIME/DIV:1ms
TIME/DIV:1ms
Note: Take long sweep time
for easy monitoring.
for easy monitoring.
oscilloscope
(AC range)
CD DECODER board
IC701 pin
#¡
TP701 pin
2
VOLT/DIV : 0.2V (with the 10:1 probe in use.)
TIME/DIV : 500ns
TIME/DIV : 500ns
0.8 to 1.8Vp-p
When observing the eye pattern, set the oscilloscope for AC
range and raise vertical sensitivity.
range and raise vertical sensitivity.
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