Y/C Circuit - LG RC-185 Service Manual

VCR ELECTRICAL TROUBLESHOOTING GUIDE

4. Y/C CIRCUIT

(1) No Video in EE Mode,
No Video in EE Mode
Does the Video signal
appear at IC301 Pin15?
YES
Is REG 5.0V applied to
IC301Pins4, 22, 47, 50, 52,
60, 84, 92?
YES
Does the Video signal
appear at IC301 Pin29?
YES
Does the Video signal
appear at the PVM02
Pin12?
YES
Does the Video signal
appear at the PVM02
Pin25?
YES
Does the Video signal
appear at the IC802
Pin29?
YES
Does the Video signal
appear at the IC901
Pin6?
NO
Check the IC802 Pin31.
NO
Check the 5.0V, 5.3VA
Line. (Power Circuit)
NO
Is I 2 C BUS signal applied to
the IC301 Pins73, 74?
NO
Check the Video Buffer
Q905.
NO
Check the DVD Board
Video path.
NO
IC802 Pins2, 4(Vcc),
Pins32, 33(I C BUS)
2
NO
Does the 12VT, 5.3VA
appear at the IC901 Pin5,6.
YES
Replace IC901.
3-11
Check the System Circuit.
NO
(Refer to 'SYSTEM I
CHECK Trouble Shooting')
YES
NO
Check the 12V, 5.4VA
Line. (Power Circuit)
2 C BUS
Check C361. (AGC)
YES
Replace IC301.