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4. TROUBLE SHOOTING
LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4.16 Touch Screen trouble
Touch Initial sequence of KC910 is :
TOUCH_VDD_2.8V(C702) goes to 2.8V
→
TOUCH_PENIRQ_N(R723),TOUCH_I2C_SCL(R720) &
TOUCH_I2C_SDA(R721) go to high
Touch operation of KC910 is :
A finger is touching on the screen
→
TOUCH_PENIRQ_N is low
→
I2C is connected
→
A finger is
took off from the Screen
→
TOUCH_PENIRQ_N is high
→
I2C is not connected.
Start
Work well?
Conne ctor Is insert?
Replace t he Main board
End
Inser t Connector, again
Yes
No
YES
NO
Touchpad Cal ibration
Replace t he Folder
Work well?
End
Yes
No
R702 (TOUCH_PENIRQ_N)
R721(TOUCH_I2C_SDA)
U703
R720
(TOUCH_I2C_SCL)
C702 (TOUCH_VDD_2.8V)
Touch Window Connector
Main FPCB Connector