LG 42lk530 Service Manual page 54

3. Trouble shooting - No video (Analog TV video)
Check RF Cable & Signal
Check Tuner 5V Power
L5101, L5103
Check Tuner 3.3V Power
L5105
Check Tuner 1.2V Power
IC5103 2 pin : 1.2V
Check CVBS Signal
TU5101 11 Pin
Check BCM LVDS Output
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Only for training and service purposes
ok
No
ok
No
ok
No
ok
No
ok
No
Replace BCM( IC101) or Main Board.
No
Check IC507
ok
Replace L5105
Replace IC5103
Bad Tuner. Replace Tuner.
Replace IC507
Replace L5101, L5103
LGE Internal Use Only