5. Power Board
1) No power
Check CN902 pin4, 5 = 5V
NG
Check AC line volt 110V or 220V
OK
Check the voltage of C908(+)
OK
Check start voltage for the pin3 of U901
OK
Check the auxiliary voltage is bigger than
10V and smaller than 20V
Check U601 pin8 PWM wave
Check IC903, IC904, Q903, ZD921, ZD922, D906, D907
NG
NG
NG
NG
OK
NG
OK
Check AC input
Check bridge rectified circuit and F901 circut
Check R904, R932, R933, and Change U901
1) Check U901
2) Check R909,D901 circuit
Check U901
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