HP L1506 Service Manual page 34

15" LCD Color Monitor
2. W/LED No Backlight
Check ON/OFF signal
Check IC801 pin5=12V voltage
Check the pin1/15 of IC801 if have waveforms
Short Q805 S D ,if the picture normal
Connect PIN4 /PIN7of IC801 and check Q805 collector waveforms
Check feedback circuit
Check C811 (+) =12V
OK
OK
OK
NG
OK
NG
OK
NG
Check Q801/Q802/Q803
NG
Check Interface board
NG
Check Q804/Q806/Q807
Change IC801
NG
Change Q805/PT801
Check connecter & lamp
34
NG
HP L1506