LG KM710 Service Manual page 67

4. Trouble Shooting
Power is supplied to
Connection between
FPCB and boards is OK?
Connectors are soldered well?
Paths of LCD control
signals are OK?
After changing the board,
LCD Display is OK?
Change the board
LGE Internal Use Only
START
the board?
Yes
First of all, push a key pad then check 1.8/2.8V
check Points during a Key pad LED ON.
Yes
Yes
Yes
You must push a key pad for a watching signals.
FPCB OK?
Yes
Yes
No
No
No
No
No
No
Copyright © 2008 LG Electronics. Inc. All right reserved.
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Refer to
Power On Trouble
Reconnect FPCB
Re-solder the
Connector
Re-solder
the EMI filter
Replace the FPCB
The LCD is broken.
Change the LCD.
Only for training and service purposes