LG KM500 Service Manual page 95

4. Trouble Shooting
z MAIN KEY Backlight LED Trouble
Is the Voltage level VBAT
LED100 ~108(Main key)
Q100(Main key) is
Backlight will work properly
LGE Internal Use Only
START
3.35 ~4.2?
YES
Are all LEDs
Working?
YES
Working?
YES
NO
Charge Battery
NO
Check the soldering of each
R or Replace LEDs not
working
NO
Check the condition of Q100
If problem, Replace Q100
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