Motherboard or PSU dying?

[Justin5609]

Lately my PC has been randomly shutting off and not powering back on until I unplug the 24pin connector from the mobo for about 30 seconds and plug it in again, and now the screen will randomly go black, all fans go to 100% and the audio buzzes loudly.

I'm leaning towards the motherboard, I've had issues with it in the past, and I THINK I it's been happening since I bought a new PSU but I cannot remember (It's gotten a lot worse lately, before I just dealt with it.)

Any way to know for sure? I don't want to drop $350 on a mobo and it still happen..

Specs:
Gigabyte x79 UP4 socket 2011 mobo
i7 3820
GTX 770 SC
Consair 850W PSU
8GB Consair RAM

 

[InvalidError]

The easiest way to find out would be to try a known-good PSU. If you have none, you might want to buy something like a 520W Seasonic S12-II for ~$60 which would be vastly sufficient for what little hardware you appear to have in there - when it comes to PSUs, quality becomes more important than quantity once the PSU meets the system's real peak requirements.

If by "Consair 850W" you meant Corsair CX850, the CX series has a long history of mixed results, so that makes it suspect even if it is relatively new.

 

[Justin5609]

Thanks for your input I'll probably try that!
Also have a 1TB HDD and 2 SSDs if that makes a difference to anything.

It's the Corsair TX850M model. Does the fact unplugging the 24pin connector from the motherboard temporarily fixing it and my GPU fan going out of whack / audio buzzing make it sound like its likely the motherboard over the PSU to you?

 

[InvalidError]

It might, or it might not.

Since you said it got worse after getting a new PSU, maybe you got unlucky and got a flaky PSU. Depending on what you had before it, there is also the possibility your previous PSU damaged the board or that you got a bad board in the first place.

Having to unplug the ATX connector before the PC/PSU will start again sounds like a strange and potentially dangerous step to me. You may want to try using the hard-switch on the back of the PSU instead and see if that works. If you have a multimeter and know how to use it, you might want to probe the back of the ATX connector while the PC is working normally and after it went nuts to see if all the voltages are still within their expected ranges.

 

[Calvinb81]

Sounds like your PSU to me, fans running at 100% normally indicates that as well as other problems. I'd get rid of that PSU before it causes further damage.