Backlight Is Not Working - LG -500 Service Manual

5.2.8 Backlight is not Working

In the TEST mode,
select Baseband Test,
then LED Test then
BackLight ON/OFF
R709 is well
connected
YES
Voltage Level
of T701 is high
(approx.3V)
YES
Voltage value
of LED PIN1 is same
as the voltage value
of battery.
YES
Replace
D701~D708
START
NO
Re-Mount the
R709
NO
Replace the T701
NO
Replace Battery
NOTE : To get to the Test mode, press
2945 ¡ #, then hold down * key.
T701 : Keylight switching TR
T704 : LCD backlight Switching TR
Defected Key
backlight
R723 is well
connected
Voltage Level
of T704 is high
(approx.3V)
Voltage value
of LED PIN1 is same as
voltage value
of Vat.
Replace
D701~D708
- 32 -
Defected LCD
backlight
NO
Re-Mount the
R718, R723, R724
YES
NO
Replace T704
YES
NO
Replace the
YES
Battery