Keypad Backlight Trouble - LG AT&T GR500 Service Manual

4. TROUBLE SHOOTING

4.9 Keypad Backlight Trouble

Key PCB problem
Check VBAT(C104) and ACC_GP_SUBLED_ON(R108)
LED ON?
Change LD100 and LD101
LGE Internal Use Only
Power on
LED ON?
Change Key PCB
Yes
LED ON?
Yes
No
ACC_GP_SUBLED_ON
START
Yes
No
No
Check FPCB connectors
Yes
Finish
VBAT
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Finish
Main PCB problem
LED ON?
No
Change Main PCB
Only for training and service purposes