Y/C Circuit - Zenith XBV323 Series Service Manual

VCR ELECTRICAL TROUBLESHOOTING GUIDE

5. Y/C CIRCUIT

(1) No Video in EE Mode,
No Video in EE Mode
Does the Video signal
appear at IC301
Pins28, 30, 32?
YES
Is REG 5.0V applied to
IC301Pins23, 44, 45, 52, 68,
77?
YES
Does the Video signal
appear at IC301 Pin26?
YES
Does the Video signal
appear at IC501 Pin52?
YES
Does the Video signal
appear at IC602 Pin7?
Does the Video signal
NO
appear at IC302
Pins1, 5?
YES
Is there 5V at IC302 Pin6?
YES
Replace IC302.
NO
Check the REG 5V Line.
(Power Circuit)
NO
Is I 2 C BUS signal applied to
IC301 Pins53, 54, 55?
YES
Check the path of the sig-
NO
nal between IC301 Pin 26
and IC501 Pins50, 52.
NO
Is there 5V on the plus
terminal of C614?
YES
Replace IC602.
3-11
Check DVD Video Input
NO
(IC802, Pin29), Tuner
Video Input (TU701 Pin24),
Line Video Input (JK801),
respectively.
NO
Check the REG 5V Line.
(Power Circuit)
NO
Check the REG 5V Line.
(Power Circuit)
Check the System Circuit.
NO
(Refer to 'SYSTEM I
CHECK Trouble Shooting')
Replace IC301.
NO
Check the REG 5V Line.
(Power Circuit)
2 C BUS