Electrical Check - Sony CDX-646 Service Manual

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)
master unit
+
GND
CONTROL connector
(CN901)
14
SECTION 5

ELECTRICAL CHECK

BUS cable
compact disc changer
Focus Bias Check
Connection:
– RF Board (Component Side) –
oscilloscope
(AC range)
+
–
TP (VC)
IC101
TP
(RFO)
Procedure:
1. Connect the oscilloscope to TP (RFO) 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.
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
(10 : 1 probe in use)
level: 1.4 ± 0.3 Vp-p