HCL HCM9LWAT11 Servise Manual page 35

19"W LCD Color Monitor
8.2.2 Power Board
No power
Check L903 = 12V
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
Check Q903/D904/IC902/ZD901/ZD902
NG
OK NG
OK NG
NG
OK
NG
OK
NG
OK
Check AC input
Check bridge rectified circuit and F901 circuit
Check R904, R931, R938, Change IC901
1) Check IC901
2) Check R909/D902 circuit
Check IC901
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HCL HCM9LWAT11