User Guide

5-18 Flow Chart of Troubleshooting and Circuit Diagrams
5-10 Back Light
Yes
END
Backlight does not work
Select backlight "ON" mode
Backlight "ON" mode
in the menu?
R575 = "H" ? GPO1 by test S/W
No
Yes
Yes
No
Resolder R575,R579
or replace Q403
Q403 pin 3 = "L" ?
LCD backlight on ? Replace LCD
No
Yes
No
LCD BACKLIGHT
KEY PCB LED
Resolder R575,R579
or Resolder Q403
Q403 pin 3 = "L" ?
No
Yes
Yes
END
Key PCB LED on ?
Resolder
R572,R573,R574,R725,R745,
R746,R747,R748 or Replace
PBA
No