Acer G195HQ Service Manual page 37

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