LG GT540 - Main LCD Trouble

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Only for training and service purposes
4. Trouble Shooting
4. 14. Main LCD trouble
Main LCD control signals are generated by MSM7227. Those signal’s path are :
MSM7227 -> LCD Module
{GsjkG
z{hy{
wGlukG
GGGG
pGGGf
mGGwGvu
G
sjkGGvrf
jGwGG
}ylnsjkXU_}GO{wXP
}ylnsjkYU_}GO{wYP
u


kGG
sjkG
jGGtGik
u
l
u
jGGsjkG


Press END key to tun the power ON
Is the circuit powered?
Yes
END
Follow the Power ON
trouble shooting
No
LCD display OK?
START
No
Check Power
VREG_LCD_1.8V(TP1)
VREG_LCD_2.8V(TP2)
No
Change the Main board
Disconnect and reconnect
LCD connector
Change the LCD module
The LCD works
Yes
Yes
Yes