Read LG 42LH70YD (CHASSIS:LJ91D) Service Manual online
2. No OSD Trouble Shooting
Replace Power board
N
Y
Check 12V Voltage Level
at P801 #13 Pin
Check Power connector
Y
Check 12V Voltage Level at L909
N
Replace one of
Q802/Q803/Q804/L801
& Recheck
Y
Check P903
#16(TXAC-), #17(TXAC+),
#32(TXBC-), #33(TXBC+)
Y
Check LVDS Cable
N
Replace Cable
Y
Check Voltage LCD Module
Check 12V Voltage Level
at L801
N
Replace one of L801/Q804
& Recheck
Y
Maybe BCM3556(IC100) or
7329A(IC901)
has troubles
Check Voltage Level 2.5V at L827
N
Replace one of IC803/L824/L827
& Recheck
Y
Check Voltage Level 1.8V
at IC802 #2 pin or L815
N
Replace one of IC802/IC805/L815
& Recheck
Y
Check Voltage Level 1.26V
at IC807 #6 pin
N
Y
N
Replace IC807
& Recheck
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