LG GT500 - Main LCD Trouble

- 87 -
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
4. TROUBLE SHOOTING
4.7 Main LCD Trouble
LCD control signals are generated by DB3200.
START
Press END Key
to turn on the power.
Is the circuit powered?
Is the R600 (TP1) 1.8V?
And
Is the R601(TP2) 2.8V?
YES
NO
Follow the Power On Trouble Shooting
Reconnect the LCD FPCB 50pin(CN2)
and 40pin (CN1) LCD connector.
Or
Change Key FPCB.
1
No
No
Change the U604
Yes
LCD display OK?
YES
Yes
LCD display OK?
Is the backlight on?
Is the backlight on?
Reconnect the LCD FPCB 50pin(CN2)
and 40pin (CN1) LCD connector.
Or
Change Key FPCB.
NO
No
The LCD works
2
Yes
Yes
The LCD works
No
Change
the U600
3
Is the LCD ID High?
(CN1 Pin3 (TP3))
No
Change
LCD
Yes
IS the CN1 Pin11(TP4) Low?
And
Is the CN1 pin 19(TP5) high?
5
No
Change
the main
board
Yes
1
6