Read LG 42SL90QD-SA (CHASSIS:LJ91L) Service Manual online
6. RGB Video Trouble Shooting
Check Signal Format
Is it supported signal?
Y
Check RGB Cable
Check RGB Jack JK208 at Jack
Board
N
Y
Check RGB Signal
L207, L208, L209 at Jack Board
N
Replace one of L207, L208, L209
at Jack Board & Recheck
Y
Check RGB Signal
C127, C128, C129 at Main Board
N
Replace it
Y
Y
Replace JK208 at Jack board
Maybe BCM3556(IC100)
has problems
Check cable between P203 at Jack
Board and P701 at Main Board
N
Maybe Cable Pin has problems
Y
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