Power/Inverter Board - AOC LM927U Service Manual

8.2.2 Power/Inverter Board

1.) No power
Check CN902 pin2, 4 = 12V
Check AC line volt 110V or 220V
Check the voltage of C905(+)
Check start voltage for the pin3 of IC901
OK
Check the auxiliary voltage is bigger than
10V and smaller than 20V
Check IC901 pin8 PWM wave
Check Q901, R914,T901,D910,D911,ZD902
NG
NG
OK
NG
OK
NG
NG
OK
NG
OK
Check AC input
Check bridge rectified circuit and F901 circut
Check R906,R907 and Change IC901
1) Check IC901
2) Check ZD901,Q902, Q903...OVP circuit
Check IC901
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AOC LM927U