LG 42LK450 Service Manual page 68

Trouble shooting guide
9. Digital TV Audio
Check RF Cable & Signal
ok
Check Tuner 5V Power
L3702
ok
Check Tuner 3.3V Power
L3703
ok
Check Tuner 1.2V Power
IC3703 2 pin : 1.2V
ok
Check IF_P/N Signal
TU3702 17/18 Pin
ok
Follow procedure
'8. All source audio'
trouble shooting guide.
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Only for training and service purposes
No
Check IC411
No
Replace L3703
No
Replace IC3703
No
Bad Tuner. Replace Tuner.
No
Replace IC411
ok
Replace L3702
※ When the PCB is EAX63529602
IC411 is not available.
In this case, check IC406 is 5V or not
LGE Internal Use Only