LG 42lk530 Service Manual page 53

2. Trouble shooting - No video (Digital TV video)
Check RF Cable & Signal
ok
Check Tuner 5V Power
L5101, L5103
ok
Check Tuner 3.3V Power
L5105
ok
Check Tuner 1.26V Power
IC5103 2pin : 1.26V
ok
Check IF_P/N Signal
TU5101 17/18 Pin
ok
Check BCM LVDS Output
Copyright ⓒ 2011 LG Electronics. Inc. All right reserved.
Only for training and service purposes
No
Check IC507
No
Replace L5105
No
Replace IC5103.
No
Bad Tuner. Replace Tuner.
No
Replace or BCM( IC101) or Main Board.
No
Replace IC507
Replace L5101, L5104
ok
LGE Internal Use Only