Read LG 42LD550 (CHASSIS:LA02B) Service Manual online
9. Digital TV Audio
Check RF Cable & Signal
Follow procedure
‘8. All source audio’
trouble shooting guide.
ok
Check Tuner 3.3V Power
L701
Replace L701
Check Tuner 1.2V Power
IC700 2 pin : 1.2V
Check IF_P/N Signal
TU700 17/18 Pin
Replace IC700
Check Tuner 5V Power
L700
ok
ok
ok
ok
No
No
No
Bad Tuner. Replace Tuner.
Check IC8003
No
Replace IC8003
No
Replace L8007
ok
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