LG G5500 Manual page 70

START
The Voltage
of KEY_LED signal
is about 0V?
Yes
Is there anything that
resistor value across LED
is under 10Ω?
No
The path is OK?
Yes
The LED is out of order.
Change the LED.
Enter into Engineering Mode
and select Keypad On
No
Operation of FPCB is OK?
Power off and Measure the
Resistor Value of all LEDs.
Yes
Replace the ALL LED.
It is out of order.
No
Resolder the path
of LED and Resistor.
-71-
Yes
ABB is out of order.
Change the Board.
No
ABB is out of order.
Change the Board.