Electrical Check - Sony CDX-848X Service Manual

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Note:
1. This check is performed with the set placed horizontally.
2. Power supply voltage: DC14.4 V (more than 3 A).
3. Be sure to use the disc "YEDS-18" parts code: 3-702-101-01, but only
when indicated.
Connection:
power supply
(DC 14.4 V)
+
GND
TE
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ELECTRICAL CHECK

master unit
BUS cable
compact disc changer
CONTROL connector
(CN901)
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SECTION 5
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8
Focus Bias Check
Connection:
– RF Board (Component Side) –
oscilloscope
(AC range)
+
–
TP (RFAC)
Procedure:
Q Q
3 6 7 1 3 1 5
1. Connect the oscilloscope to TP (RFAC) and TP (VC) on the
RF board.
2. Put the set into play mode by loading the disc (YEDS-18).
3. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
Note:
Clear RF signal waveform means that the shape "◊" can be clearly distin-
guished at the center of the waveform.
RF signal waveform
When observing the eye pattern, set the oscilloscope to AC range
and raise the vertical sensitivity so that it may be easily seen.
co
.
CDX-848X
9 4 2 8
TP (VC)
IC101
0 5 8 2 9 9 4 2 8
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
(10 : 1 probe in use)
level: 1.4 ± 0.3 Vp-p
m
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