AOC LM927U - Page 37

AOC LM927U
37
2.) No Backlight
Check Q205/Q207/Q203/D201
Check Q206/Q208/Q204/D202
Check C201 (+) =12V
Change F902
Check ON/OFF signal
Check main board
Check U201 pin9=12V
Change Q201 or Q202
Check the pin1 of U201 have sawtooth wave
Change U201
Check the resonant wave of pin2 & pin5 for PT201/PT202
Check the output of PT201/PT202
Check Q209/Q210/C213
Check Q211/Q212/C214
Check connecter & lamp
OK
OK
OK
OK
NG
NG
OK
NG
NG
NG
OK
NG
NG
OK
Replace PT201/PT202
Check D201/D202 have the output of square ware at short time
http://www.wjel.net