Dell E228WFP Service Manual page 46

22" LCD Color Monitor
No Backlight
Check CN902=12V
OK
Check ON/OFF signal
OK
Check U801 PIN2=5V
OK
OK
OK
Check Q802, Q809, Q812, Q813 Drain wave
OK
Check the output of T801, T802, T804, and T805
OK
Check connecter & lamp
NG
NG
NG
Check U801 PIN13 have triangle wave
NG
Check U801 PIN1/PIN15 PWM wave
NG
NG
NG
Check adapter and F902
Check Interface board or main board
Change on/off circuit
Change U801
Check Q805/Q811
Check Q802, Q809, Q812, Q813
Change T801, T802, T804, and T805
46
Dell E228WFP