8
D-FJ737
Procedure:
1. Connect the oscilloscope to the test points TP629 (RF) and TP635
(GND) on the MAIN board.
2. Set a disc. (YEDS-18)
3. Press the
u
button.
4. Check the oscilloscope waveform is as shown below.
A good eye pattern means that the diamond shape (
◊
) in the cen-
ter of the waveform can be clearly distinguished.
RF Signal reference Waveform (Eye Pattern)
To watch the eye pattern, set the oscilloscope to AC range and
increase the vertical sensitivity of the oscilloscope for easy
watching.
5. Stop revolving of the disc motor by pressing the
x
button.
SECTION 4
ELECTRICAL ADJUSTMENTS
The CD section adjustments are done automatically in this set.
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 button : Minimum
AVLS switch : NORM
HOLD switch : OFF
Focus bias Check
Condition:
• Hold the set in horizontal state.
Connection:
RF level
0.45 to 0.65 Vp-p
VOLT/DIV : 100 mV (With the 10 : 1 probe in use)
TIME/DIV : 500n
s
IC501
D461
C505
R649
IC402
IC604
C622
C461
R506
R461
TP818
R654
TP922
TP635
(GND)
TP637
TP638
R463
TP912
Q501
R624
TP641
R635
C625
C646
TP403
TP911
R653
R647
C605
C609
R504
R652
R462
TP
R625
TP501 TP503
FB602
TP502
TP504
C620
FB603
TP417
C631
C632
C630
R657
R104
R505
D602
C645
TP633
TP629
(RF)
TP630
C635
C636
C502
TP632
C506
C462
R655
C507
C628
C626
C624
C623
R656
TAP602
TP302
TAP403
TP920
TP915
C634
TP631
R5
R4
1
6
7
12
24
19
18
13
IC602
1
3
4
5
1
3
4
5
1
8
9
16
MAIN BOARD (SIDE B)
TP629 (RF)
TP635 (GND)
2 K
Ω
oscilloscope
(AC range)
www. xiaoyu163. com
QQ 376315150
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TEL 13942296513
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TEL 13942296513 QQ 376315150 892498299
TEL 13942296513 QQ 376315150 892498299
