22" LCD Color Monitor ASUS VK222U/S
40
8.2.2 Power/Inverter Board
1.) No power
Check CN902 pin4, 5 = 12V
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 IC901
Check R904, R932, R933 and Change IC901
NG
Check the auxiliary voltage is bigger than
10V and smaller than 20V
1) Check IC901
2) Check R909, D901 circuit
OK
OK
NG
Check IC903, IC904, Q901, ZD921, ZD922, D915, D916
OK
Check IC901 pin6 PWM wave
OK
Check IC901
NG
NG
NG
OK
NG
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