D-EJ855 SECTION 4 ELECTRICAL CHECK
The CD section adjustments are done automatically in this set. In case of operation check, confirm that focus bias. Precautions for Check 1. Perform check in the order given. 2. Use YEDS-18 disc (Part No.: 3-702-101-01) unless otherwise indicated. 3. Power supply voltage requirement: DC4.5 V in DC IN jack. (J401) VOLUME : Minimum AVLS switch : NORM HOLD switch : OFF G�PROTECTION switch : 1
R604 C606 K A R305 + C404 C449 C301 VDR303 FB101 55
Focus bias Check Condition: � Hold the set in horizontal state. Connection:
oscilloscope (AC range) MAIN board TP601 (RF) TP418 (GND) 2k�
+ �
Connecting and Checking Location: � MAIN Board (Component Side) �
Procedure: 1. Connect the oscilloscope to the test points TP601 (RF) and TP418 (GND) on the MAIN board. 2. Set a disc. (YEDS-18) 3. Press the > N button. 4. Check the oscilloscope waveform is as shown below. A good eye pattern means that the diamond shape (�) in the center of the waveform can be clearly distinguished.
VDR101 C102
RF Signal reference Waveform (Eye Pattern)
TP418 (GND)
J301 LINE OUT (OPTICAL)
VOLT/DIV : 100 mV (With the 10:1 probe in use) TIME/DIV : 500 ns
TP601 (RF)
RF level 0.4 to 0.6 Vp-p
D403
R489
1
R410
VDR304
OPTICAL PICK-UP BLOCK DAX-25E
CN503
VDR301
FB201 VDR201
To watch the eye pattern, set the oscilloscope to AC range and increase the vertical sensitivity of the oscilloscope for easy watching.
R303 R304
C605
12
13
C202
C448
R102
R602 R601 C601 R603 C603
C604
IC404
R469
15
1
24
FB301
5. Stop revolving of the disc motor by pressing the x button.
