Keypad Back Light Trouble - LG KM380t Service Manual

6.10 Keypad back light trouble

Check Points
-Signal path is connected well
-Analog SW is working properly
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VBAT
TP1
R593
KEY_BL_EN
100K
START
Check All of LEDs solder
Check VBAT
Yes
check GPIO
signal(KEY_BL_EN,
TP1) Voltage of Q402
> 0.7v
Yes
KEY_LED is operating
KEY LED
No
Check BATTERY
No
Replace TR(Q402)
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6. Trouble shooting
LGE Internal Use Only