ASI DW19MBD, Service Manual

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19" LCD Color Monitor ASI DW19MBD
31
8.2.2 Power Board
1) No power
Check L904 = 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 pin3 of IC901
Check R904, R932, R933, Change IC901
NG
Check the auxiliary voltage is bigger than
10V and smaller than 20V
1) Check IC901
2) Check R909/D901/C908 circuit
OK
OK
NG
Check Q901/D903/IC903/ZD921/ZD922/Q903
OK
Check IC901 pin8 PWM wave
OK
Check IC901
NG
NG
NG OK
NG