Y/C Circuit - LG LGXBR342 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 PMD02 Pin7?
YES
Does the Video signal
appear at the PMD02
Pin5?
YES
Does the Video signal
appear at the JK602
Video Out Jack?
Check VDR Video Input
NO
(PMD02 Pin 5), Tuner Video
Input (TU701 Pin24), Line
Video Input (IC602 Pins 1, 3,
5, 7), respectively.
NO
Check the REG 5V Line.
(Power Circuit)
NO
Is I C BUS signal applied to
2
IC301 Pins53, 54, 55?
YES
Check the path of the sig-
NO
nal between IC301 Pin 26
and IC501 Pins50, 52.
NO
Is there REG12 on the
plus terminal of C653?
YES
Check the Q605
(Video Buffer)
NO
Check the VDR
Module
NO
Check the IC601 and
Video Out Line
3-11
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 12V Line.
(Power Circuit)
C BUS
2