Asus VH236H Service Manual page 76

Service Manual
11.2 Power/Inverter Board
1.) No power
Check L904 = 16V
NG
Check AC line volt 110V or 220V
Check the voltage of C905 (+)
Check start voltage for the pin3 of U901
Check the auxiliary voltage is bigger than
11V and smaller than 25V
Check U901 pin8 PWM wave
Check Q901, IC903, IC904, D906, D907, D906, ZD921, ZD922
NG
OK
OK
NG
OK
OK
OK
Check AC input
NG
Check bridge rectified circuit and F901 circuit
Check R904, R905, R906 and Change U901
NG 1) Check U901
2) Check R910, D903 circuit
NG
Check U901
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ASUS VH236H&VH232H