Sony XES-Z50, Service Manual

Page: 48 / 153

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TRACKING OFFSET ADJUSTMENT
Condition: This adjustment is performed with the set place hori-
zontally.
Connection:
+
– TP (TE)
TP (VC)
DRIVER board
oscilloscope
(DC range)
Adjustment Procedure:
1. Connect the oscilloscope to TP (TE) and TP (VC) on the
DRIVER board.
2. Put the set into play mode by loading the disc (YEDS-18).
3. Press the cursor buttons on the wireless remote commander,
observe the traverse waveform *.
4. Adjust the RV101 on the DRIVER board so that the oscillo-
scope reading is symmetrical in relation to 0 ± 0.05 V.
* Traverse waveform: This is the tracking error waveform appears
when crossing the track.
VOLT/DIV : 1 V (with the 10: 1 probe in use)
TIME/DIV : 2 msec
CENTER : 0 ± 0.05 V
Connection and Adjustment Location: DRIVER board
(See page 50)
CD SECTION
Notes:
1. Perform adjustments in the order given.
2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise
indicated.
3. Use the oscilloscope with more than 10 M
Ω
impedance.
4. Power supply voltage requirement: DC 14.4 V
(more than 3 A)
5. In making adjustment, connect the control unit and changer
unit.
FOCUS BIAS ADJUSTMENT
Condition: This adjustment is performed with the set placed hori-
zontally.
Connection:
Adjustment Procedure:
1. Connect the oscilloscope to TP (RF) and TP (VC) on the
DRIVER board.
2. Put the set into play mode by loading the disc (YEDS-18).
3. Adjust the RV102 on the DRIVER board so that the waveform
on the oscilloscope (eye pattern) is good.
A good eye pattern means that the diamond shape (
≈
) in the
center of the oscilloscope can be clearly distinguished.
•
RF signal reference waveform (eye pattern)
+
– TP (RF)
TP (VC)
DRIVER board
oscilloscope
(AC range)
VOLT/DIV : 200 mV (with the 10: 1 probe in use)
TIME/DIV : 0.5 µsec
1.1 Vp-p
+0.3
–0.2
Note: When observing the eye pattern, set the oscilloscope to
AC range and raise the vertical sensitivity so that it may
be easily seen.
Connection and Adjustment Location: DRIVER board
(See page 50)






A
B
0
±
0.05 V
C=1.8
±
0.3 V
traverse waveform
(100 track jump waveform)
C