SONY DVE45 Repair Manual

D-VE45
SECTION 4
ELECTRICAL ADJUSTMENT
CD section adjustments are done automatically in this set.Test Points:
In case of operation check, confirm that focus bias.
� MAIN BOARD � (SIDE B)
4-1. PRECAUTIONS FOR CHECK
1. Perform check in the order given.
2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwiseJ302
indicated.
3. Power supply voltage requirement: DC 4.5 V in DC IN jack.
(J401)
VOLUME button : Minimum
HOLD switch: OFF
4-2. FOCUS BIAS CHECK
Condition:
Y Hold the set in horizontal state.
Connection:
oscilloscope
(AC range)
2 k&
MAIN board
TP629 (RF)
TP629 (RF)
Procedure:
1. Connect the oscilloscope between TP629 (RF)
and GND on MAIN board.
2. Insert the disc (YEDS-18). (Part No. : 3-702-101-01)
3. Press the N > button.
4. Confirm 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.
5. Stop revolving of the disc motor by pressing the x button.
Y RF signal reference waveform (eye pattern)
VOLT/DIV : 50 mV (10 : 1 probe in use)
TIME/DIV : 500 nS
RF level :
0.6 ? 0.2 Vp-p
When observing the eye pattern, set the oscilloscope for AC range
and raise vertical sensitivity.
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