Acer Aspire One No Power

[ry x hunter]

hello i have a problem with acer aspire one 722.
The gate of the p-channel mosfet is high and no voltage measured on drain.
but the mosfet is good.. please help
i attached the schem for other info ..

[angel-boy]

Re: Acer Aspire One No Power

You have a short after mosfet that is why you have low vontage on pin 4.

Your gate is 19v, and to open should be ~25-28v.

Check with a laborator power supply, give like 1-2v and see how many amps "eating"

[fddizon]

Re: Acer Aspire One No Power

connect to a dc bench ps. take note of the voltage reading and the amps.

then remove or place a jumper from source to drain of the fet in question, inject voltage from a dc bench setting lower than 1 volt also start from lower amp. find the one thats heating up while feeding supply from dc bench. if none found on the initial settings, try adding more amps gradually while looking for the culprit.

without a dc bench ps, check coils which id shorted to ground. also check the output of the fet (19v rail) if shorted to ground. if coils found, remove the coil and check the FETs and ceramic capacitors on that section.

hope this helps

[khaahk]

Re: Acer Aspire One No Power

isl6251 pin2 voltage is?

[ry x hunter]

Re: Acer Aspire One No Power

isl6251 pin2 voltage is?

0.7 volts sir

[khaahk]

Re: Acer Aspire One No Power

Check pr24 and pr28 resistances. If they are ok - PU2 might be the cause.