3.Power Board
1)No power
Check CN902 PIN6, 7 = 5V
NG
Check AC line volt 110V or 220V
OK NG
Check the voltage of C907 (+)
OKNG
Check start voltage for the pin8 of U901
NG
OK
Check the auxiliary voltage is bigger than 11V and smaller than 25V
Check AC input
Check bridge rectified circuit and F902 circuit
Check R908 and Change U901
OKNG
Check U901 pin5 PWM wave
1)Check U901
2)Check D907/Q901 circuit
OKNG
Check U901
Check D902/ Q906/Q904/U902/ZD901/U903
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