Computer suddenly stopped working, now works (?) again

[FrederikNeertof]

Hey everyone.

I have a problem with my desktop PC.
A few weeks back it suddenly stopped working one day and I wasn't able to turn it on (nothing happened when I pressed the power on button). I tried unplugging everything, resetting the CMOS, installing a new power cord but nothing helped. I tried doing everything above again 3 days later but it still didn't work.

A week after this, I randomly tried turning my computer on, and it actually worked fine - for a few hours, before it turned off by it self and wouldn't work. Of course, it didn't work the following week after, either. It started about a month ago and just today I tried turning it on again, surprised to see that it actually works (it has been running for 1 hour now). Something I noticed is that the fans seems to be spinning faster and are louder than normal.


I checked the tempatures and they looked like this: (see added screenshot)

My PC specs are the following:

Windows 7 Ultimate 64 SP1
AMD Phenom II X4 965 3,60 GHz
4,00 GB DD3
Radeon HD5850
Gigabyte Ultra Durable 3 GA-870A-UD3

Does anyone have a clue what's wrong?

Any help would be greatly appreciated.

Sorry if it all sounds confusing, but this is the best I could describe it

 

[Cobalt006]

Have you tried another power supply for it?

 

[FrederikNeertof]

Have you tried another power supply for it?

No, I haven't

Is there a way to check if its the power supply that's causing the problem without replacing it?

 

[Cobalt006]

You can try swapping it out with another one. That is if you have a spare. Or you can test it with a multimeter.www.pcsupport.about.com/od/toolsofthetrade/ht/power-supply-test-multimeter.htm