BenQ G900WA, Service Manual

Page: 39 / 58

19” LCD Color Monitor BenQ G900WA
39
Power/Inverter Board
No power
Check bridge rectified circuit and F901 circut
1) Check IC901
2) Check R909,D901, C908…OVP circuit
Check CN902 pin4, 5 = 14V
Check the voltage of C905(+)
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
NG
NG
NG
Check Q902/D906/IC903/ZD921/ZD922
Check IC901 pin6 PWM wave
1)Check IC901 Check
NG
OK
NG
OK
OK
OK
OK
Check AC line volt 110V or 220V
Check AC input