Acer X233H

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5. Power 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 pin3 of IC901
Check R904, R905 and Change IC901
NG
Check the auxiliary voltage is bigger than
11V and smaller than 25V
1) Check IC901
2) Check R909/D901/C908/C907circuit
OK
OK
NG
Check D906/D907/D908/IC903/Q903/ZD902
OK
Check IC901 pin8 PWM wave
OK
NG
NG
NG
OK
NG
Check IC901