Acer X223HQ Computer Monitor User Manual


 
34
5. Power Board
1) No power
Check F801 = 14.5V
Check AC line volt 110V or 220V
Check AC input
Check the voltage of C907 (+)
Check bridge rectified circuit and F901 circuit
Check start voltage for the pin8 of U901
Check R908, R911 and Change U901
NG
Check the auxiliary voltage is bigger than
11V and smaller than 25V
1) Check U901
2) Check R913, D904 circuit
OK
OK
NG
Check Q901, U902, U903, D901, D902, D906,ZD901,Q904
OK
Check U901 pin5 PWM wave
OK
NG
NG
NG
OK
NG
Check U901