TCL L22E75BK Service Manual page 25

22 " LCD TV
5.3 No display (LED indicator green)
Check IC801 PIN11/PIN12/PIN19/PIN20 have PWM
Check the output of PT801, PT802
Check F902=12V
OK
Check ON/OFF signal
OK
Check IC801 PIN5=5V
OK
wave
OK
Check Q801/Q805/Q811/Q812 have PWM wave
OK
OK
Check connecter & lamp
TCL L22E75BK
NG
Check F902/ZD920/F904/D906/C918
NG
Check Interface board or main board
NG
NG
Change IC801
NG
Check the transistor
NG
Change PT801, PT802
25
Change on/off circuit
Q802/Q803/Q804/ZD803