Computer won't turn on....Power Supply Problem?

[pickupartist3]

All of the sudden today my computer will not turn on at all. No noises, no whirring, no lights.... nothing seems to be getting any power. I checked all the connections inside and everything seemed pretty good. Re-checked the switch for the supply and of course checked the plugs on both ends. Then I tried in another room and still nothing. The other day when I was out of the house my roommates told me that the tower was making a strange beeing noise and the monitor said that my video card wasn't being recognized. It's the second time they told me that in the last week, but I checked the connections and they were fine...plus it worked in between so I didn't think anything of it. I was never there to see it myself, so this is the best I can do but I figured it was worth mentioning. Do you think it is a problem with my Power Supply or is the whole motherboard shot? (Or other?). I built the computer myself but have been out of the loop for a few years and have no clue how to troubleshoot this one. Any help is appreciated. This is the first time anything like this has ever happened. Thanks for your help.

 

[JamesE]

Could be either, but that sounds like PSU to me. I've had a couple MB's die that wouldn't power up, but fans would still spin in those cases for me. Nothing at all, that sounds like a power issue.

 

[Nenu]

Unplug the psu from everything except the mains and switch it off.
Short the green wire to black on the big motherboard connector.
Switch it on, it should power up and stay powered up as long as the short is in place.

Let us know the result.