LG KE590 Service Manual page 71

4. TROUBLE SHOOTING
FPCB and boards is OK?
Connectors are soldered well?
Paths of LCD control
After changing the board,
Change the board
LGE Internal Use Only
START
Power is supplied to
the board?
Yes
First of all, push a key pad then check 1.8/2.8V
check Points during a Key pad LED ON.
Connection between
Yes
Yes
signals are OK?
Yes
You must push a key pad for a watching signals.
FPCB OK?
Yes
LCD Display is OK?
Yes
No
Power On Trouble
No
No
No
No
Replace the FPCB
No
The LCD is broken.
Change the LCD.
Copyright © 2007 LG Electronics. Inc. All right reserved.
- 72 -
Refer to
Reconnect FPCB
Re-solder the
Connector
Re-solder
the EMI filter
Only for training and service purposes