ATX powersuply turn on?

[Randog77]

How does an ATX motherboard turn an ATX powersupply on? I have an Asus SK8N that will not turn the powersupply on. I think the problem is the motherboard, but I want to know, does the motherboard need a working proccesor to turn the powersupply on. I'm hoping my Athlon FX-51 is not dead, and just the motherboard gave up the ghost. Thanks.

 

[glugglug]

ATX powersupplies are always on unless you either unplug them or flip the switch in the back (not all of them have the switch).

There is a "power good" line on the motherboard power connector that will keep the powersupply from powering the drives and fans if the voltages it senses are too far out of whack. The motherboard may require a working CPU before it signals this line.

If you had a power outage and your powersupply is one of the ones without the switch in back it might require you to unplug it and plug it back in before it will go on again.

 

[AbsolutDealage]

Unplug the ATX connector from your board. Grab your handy-dandy volt meter, and measure between pin 8 (usually gray wire) and pin 7 (or any other black wire, for that matter). If this reads >2 volts, then it probably is not your supply.

 

[lexxmac]

Just so you know, you can ground the power-on pin on an atx connector to force the power supply to go into full power mode. Most of the time its a green wire. Maybe not totally relevant but just so you know...

 

[GoHAnSoN]

Originally posted by: lexxmac
Just so you know, you can ground the power-on pin on an atx connector to force the power supply to go into full power mode. Most of the time its a green wire. Maybe not totally relevant but just so you know...

yeah, just do this, if the psu fires, u should hear some fan noise.
if not, time to change new psu 🙂