PC won't power up, motherboard has power (more details)

[Rainbowtrout11]

So yesterday my PC worked fine. It always has. Its a powerful custom gaming computer with a 750w power supply and an Asus mother board.

Anyway, it worked fine. Today I tried to power it up and nothing happened. This has happened befor . Ihad to unplug the power cable, mess with the switch, etc before the power button would turn it on. But it always did, until today. So I figured a cable came loose. Turned out the part where the cords from the case itself plugged in, where the speaker (that beeps when powered up, the power/reset buttpm , etc are plugged in.. Uh.. Turned out the part that controlled the power button was loose. So I pushed it back in and plugged the bit back into the board.

The PC powered on but it shut down immediately after 2 seconds. Everything. I don't know what caused this. My only guess is that the power supply is out of juice (judging from me having to do alot just to start it up in recent months) but I want to know for sure before I replace it.

Its worth noting that everything in this rig is 4 and a half years old, except the video card.

Thanks!

 

[Rainbowtrout11]

Sorry, I forgot to mention that when I plugged the bit in the PC immediately powered on. The power button still did nothing

 

[kawininjazx]

I would remove everything plugged into the motherboard and see if it stays on. If not remove the video card.

You may also want to take out the memory after that.

If it still cuts off after removing all your drives, card, ram, etc. either the board is bad or your PSU.

 

[Rainbowtrout11]

Mind walking through that? I don't want to break it. Like, what do i take out, what to do after removing the memory, video card, et .

 

[Rainbowtrout11]

Actually, did it. I think its then power suppl . Thanks!

 

[Rainbowtrout11]

I replaced the PSU but still the same problem without the video card and the RAM. Any idea what else it could be? Could the bit with the power/LCD stuff be set up wrong?

If it's my motherboard how do I go about replacing it?

Thanks.

 

[galactigus]

Unplug the case power connectors and try shorting the 2 pins on the mobo.
http://www.youtube.com/watch?v=BZqunOrUWeM
Skip to 1:30 if you don't know how to do this.

Make sure all cables are plugged in and secure as well.

 

[Rainbowtrout11]

Thanks but I don't see anything like the prongs in the video. I have an Asus M4A78T-E

 

[galactigus]

Should be the 2 pins that your cases power button is connected to you just have to unplug them.
Usually labeled Power Switch in your manual or on your board maybe as PWR_SW
http://img204.imageshack.us/img204/8682/connectedzm9.jpg

 

[kawininjazx]

More than likely it's your board. You can probably find the same one on ebay cheap.

 

[Rainbowtrout11]

Bump?

 

[Rainbowtrout11]

My bad, didnt see the answer . Thanks guys

 

[galactigus]

The only reason I suggest you shorting those pins is because if there is a problem with the wiring of your case's power button then getting a new board wouldn't fix anything I would at least eliminate the possibility of it being your case by bypassing that and trying to start the mobo manually.