System Instability

[Silence]

Hi guys,

Recently I've been having bother with my system hanging. Basically, the screen goes black and that's it. It'll either do that or just hang (mid game, for example). It's a bit sporadic. It'll happen when I'm in games, but more often it'll happen during the night while I'm away from the computer. At night, the most it'll be doing is downloading something. I don't leave it to do anything more complex than that during the night.

It's been a while since I've been diagnosing these problems, so I can't really remember what all I need to do to narrow down the problem.

Can any of you suggest the avenues through which I should go to narrow down the problem?

My system specs, for reference:

Intel i7-4770k (standard - not overclocked, undervolted, anything like that)
16GB RAM (Crucial ULP, I think)
Asus Z87-PRO
2x MSI GeForce GTX970
Asus AC-68 WiFi card
Seasonic 520w fanless PSU
About 5 various SSDs, an 840 EVO, Crucial MX100, Crucial M500, OCZ Agility 3 and a Sandisk Extreme.

There's also various other things plugged in, an Asus ROG Swift monitor, and another Asus 27" 144Hz thing (I forget the model of it)... peripherals and an Asus USB sound 'card', webcam, that sorta rubbish.

I know the PSU's relatively low wattage looks like it could be the cause of the issues, but I had done numerous calculations, trying to be as accurate as possible to see if it would be fit to handle it. I had calculcated that it would, even given the reduction in PSU performance over a given period of time. However, the usual point is, it's happening in the middle of the night when the system isn't doing anything at all, so power is unlikely to be a concern.

At this point I've been working long hours and haven't really done very much. I was going to do an OS reinstall to rule that out, but I'll need a good day to do that so that I can get it back to where it was before.

Any info would be very greatly appreciated.

Thanks

 

[Silence]

That doesn't really tell why it's all going belly up in the middle of the night when it's not doing anything.

The PSU seems only slightly warm under load (it's apparently transferred to the exterior of the PSU as opposed to being blown away by a fan), and the system is well cooled with case fans when I start gaming. The TDP per card is only 145w and I run it at a 80% TDP, leaving 232w of power used at maximum for the pair of cards. Given this, I am still very much in doubt that I'm killing my PSU with it given that the CPU does not run at the full 84w load while I'm gaming, far from it. I usually undervolt the CPU massively to lower that power figure even more (I think at this point my maximum was about 50w), but I've removed this in order to rule it out as a possible culprit for system hanging.

 

[Silence]

I haven't had a chance yet. I was hoping there would be some sort of tests I could run on the RAM, CPU, graphics cards, etc. to narrow down where the problem might be coming from. I plan on doing the easy things first until I have a week or two off to get stuck into it properly. For example, I can run stress tests on these things while I'm sleeping and won't lose too much time doing so.

My first step is to remove a couple of those SSDs. While they're not drawing much power (especially in idle), they're extra complications that can be very easily ruled out. I might try pulling out the webcam and stuff like that... since I suppose they've caused systems to crash in the past, so no reason to assume that they won't now!

Are there tests available to test SSDs for things that may be causing system instability? I've been out of the loop for so very long.