Sub Keypad Backlight Troubleshooting - LG GU280 Service Manual

4.13 Sub Keypad Backlight Troubleshooting

Sub Key Pad Back Light is on as below :
Key pressing LED_CON go down low (below 0.8v)
+VPWR is above 3.2V?
Check RA101
below 0.8v
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Only for training and service purposes
Start
Key press
Yes
Yes
LED ON ?
Yes
END
Sub Key Backlight LED On
NO
Check battery
NO
Change the FPCB
OR KEY PCB
NO
Change the MAIN PCB
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4. TROUBLE SHOOTING
LGE Internal Use Only