19" LCD Color Monitor AOC 931Fwz
37
8.2.2 Power/Inverter Board
1.) No power
Check CN902 pin3, 4= 5V
Check AC line volt 110V or 220V
Check AC input
Check the voltage of C905 (+)
Check bridge rectified circuit and F901 circuit
Check start voltage for the pin8 of U901
Check R904, R905, R906 and
Change U901
NG
Check the auxiliary voltage is bigger than
10V and smaller than 20V
1) Check IC901
2) Check R909, D900 circuit
OK
OK
NG
Check Q901, D900, IC903, IC904, ZD921, ZD922
OK
Check U901 pin8 PWM wave
OK
Replace U901
NG
NG
NG
OK
NG
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