eMachines E191W Service Manual page 42

2.) No Backlight
Check F801=12V
OK
Check ON/OFF signal
OK
Check IC801 PIN12=15V
OK
Check IC801 PIN5 have triangle wave
OK
Check IC801 PIN9/PIN10 PWM wave
OK
Check Q802 Drain wave
OK
Check the output of T801
OK
Check connecter & lamp, feedback and protect circuit
NG
Check adapter and F801
NG
Check Interface board or main board
NG
Change on/off circuit
NG
NG
Check IC801
NG
NG
42
Change IC801
Check Q801/Q804/Q811/Q812
Change T801