No Power - Main Pcba; Trouble Shooting Guide - LG 22LN4050 Service Manual

1. NO POWER-Main PCBA
NO POWER
1
Is Adapter
Output VOLTAGE 19.4V
through of JK700?
2
Is 3.3V at C708?
3
Is 1.8V at C745?
is 1.25V at C742?
4
Check waveform of X501
5
is 3.3V at 1pin of P120?
when push power key,
Is 0v at 2pin of P120?
6
is there any waver at 11pin of P120,
when use remote controller?
Insert F/W
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Only for training and service purposes
TROUBLE SHOOTING
YES
YES
YES
YES
YES
- 13 -
NO
check open or short at Line.
or change Adapter.
check the Lines of IC701,
NO
If there is any problem at Line,
check the Lines of IC711,IC704
NO
If there is any problem at Line,
Change IC704,IC706.
Check Line short or open between
NO
Change IC501 or change X501
NO
Or check Line short or open of P120
NO
Or check Line short or open of P120
4
X501
Change IC701
IC501 and X501,
Change control
change IR board
LGE Internal Use Only