LG LGXBR342 Service Manual page 22

VCR ELECTRICAL TROUBLESHOOTING GUIDE
3. Y/C CIRCUIT
(4) When the Video signal doesn't appear on the screen in REC Mode,
REC mode
Is EE mode normal?
YES
Is brightness normal?
Is the brightness signal sup-
plied to IC301 Pins18?
YES
Check the power of Pins23,
44, 45, 52, 68, 77.
Check the REG 5V power
A
YES
Is V.H SW supplied to
IC301 Pin57?
YES
Does the FM signal appear
at IC301*?
YES
Replace the IC301.
NO
Check the EE mode
YES
Is color normal?
NO
Does signal appear at
IC301 Pins41, 50?
Is 5V supplied to IC301
Pins23, 44, 45, 68, 77?
Is Y/C Bus applied to
IC301 Pins53, 54, 55?
Do X301 and X-TAL
oscillate?
NO
Check system part
(V.H/SW)
NO
Check the drum
*OPTION
Pins72, 73, 74(SP)
Pins65, 66, 67(EP)
3-14
YES
NO
YES
NO
NO
YES
NO
YES
NO
A
Check X301 oscillation
frequency.
Check the 5V power
Check system part
Check X301