Power/Inverter Board Troubleshooting - BenQ G900WA Service Manual

19" LCD Color Monitor
Power/Inverter Board
No power
Check CN902 pin4, 5 = 14V
NG
Check AC line volt 110V or 220V
OK
Check the voltage of C905(+)
OK
Check start voltage for the pin8 of IC901
OK
Check the auxiliary voltage is bigger than
10V and smaller than 20V
Check IC901 pin6 PWM wave
Check Q902/D906/IC903/ZD921/ZD922
NG
NG
NG
NG
OK
NG
OK
Check AC input
Check bridge rectified circuit and F901 circut
Check R904, R932, R933, and Change IC901
1) Check IC901
2) Check R909,D901, C908...OVP circuit
1)Check IC901 Check
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BenQ G900WA