HCL HCM9LWAN21 Service Manual page 34

19"W LCD Color Monitor
No backlight
Check the input voltage of 12V
OK
Check ON/OFF signal
OK
Check U811 PIN2=12V
OK
OK
OK
OK
Check the output of PT801, PT802
OK
Check connecter & lamp, feedback and protect circuit
NG
NG
NG
Check U811 PIN13 have triangle wave
NG
Check U811 PIN1/PIN15 PWM wave
NG
Check Q821, Q841 Drain wave
NG
NG
Check adapter and F101
Check Interface board or main board
Change on/off circuit
Change U811
Check U811
Change Q821, Q841
Change PT801, PT802
34
HCL HCM9LWAN21