HCL HCMDLWBT21 Service Manual page 33

15.6" LCD Color Monitor
8.2.2 Power Board
No power
Check L904 = 12V
Check AC line volt 110V or 220V
Check the voltage of C907 (+)
Check start voltage for the pin3 of IC901
Check the auxiliary voltage is bigger than
10V and smaller than 20V
Check IC901 pin8 PWM wave
Check Q901/D903/IC902/ZD921/ZD922/Q903
NG
OK NG
OK NG
NG
OK
NG
OK
NG
OK
HCL HCMDLWBT21&HCMDLWBN21
Check AC input
Check bridge rectified circuit and F901 circuit
Check R904, R932, R933, Change IC901
1) Check IC901
2) Check R909/D901/C908 circuit
Check IC901
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