BenQ LCD G2320HD Service Manual page 65

23" LCD Color Monitor
Power Board
No power
Check CN902 PIN3, 4 = 5V
Check AC line volt 110V or 220V
Check the voltage of C905 (+)
Check start voltage for the pin8 of IC901
Check the auxiliary voltage is bigger than
10V and smaller than 20V
Check IC901 pin5 PWM wave
NG
OK NG
OK NG
OK
OK
OK
Check D907/D908/IC903/IC904/ZD902
Check AC input
Check bridge rectified circuit and F901 circuit
NG
Check R904, R905, Change IC901
1) Check IC901
NG
2) Check R909/D901/C908 circuit
NG
Check IC901
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BenQ G2320HD