LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
4. TROUBLE SHOOTING
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4.12 Keypad Backlight Troubleshooting
Key Pad Back Light is on as below :
Key pressing
→
KYBD_BACKLIGHT go to 0V
→
Main LED On
Start
Change the Main board
Check battery
NO
Yes
Yes
Key press
Change the Main board
Yes
NO
VPWR is above 3.2V?
VA515 is 0V ?
VA515
+VPWR
+VPWR
+VPWR
Summary of Contents for TU550
Page 1: ...Date May 2007 Issue 1 0 Service Manual Model TU550 Service Manual TU550 Internal Use Only ...
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