Which component is failing in my PC?

[Ulldott]

Problem:
PC keeps crashing, mostly during games/load. Sometimes the screen goes black, GPU fan goes to 100% speed and I have to use the power button to restart. Other times just the video driver crashes(and whatever game I was playing), and lots of tiny square artifacts appear, but windows keeps running with internet, but I have to restart to get rid of the artifacts.

SPECS & TEMPS
Mobo: z68x-ud3h-b3
CPU: Intel Core i7 2600k - temp is around 40-45°C
PSU: Corsair GS700
RAM: 2x Corsair Vengeance 4GB DDR3 1600Mhz
GPU: HIS AMD Radeon HD 6950 2GB - 60°C idle, 80-85°C during load. It only has 1 fan.
SSD (windows) 64GB M4 Crucial
HDD (storage) idk, but crashes still happen with it disconnected
I use an external DAC for audio.
OS: Windows 7 Professional 64bit (Not pirated)

None of this has worked so far:
Reinstalled windows, and updated all drivers.
Borrowed a 7950 and 6570. Crashes kept happening, so it can't possibly be a bad GPU.
Tried another PSU, still crashed.
Tested one ram module at a time (I have 2) in different slots, still no good.
Inserted all 3 GPUs, one at a time obviously, in the other PCIE slot further down from the CPU, but I couldn't even boot then.

Also..
Nothing is overclocked. More recently, movies in VLC and YouTube videos aren't even playing smoothly. I can use my PC for hours as long as I stay away from games and demanding tasks. The system speaker does beep once during startup like it should. I suspect it is the so-called ultra durable motherboard which is starting to fail, but I'm not sure, so can anyone confirm this? I don't want to spend money on the wrong thing.

 

[T3CHN0RRI5]

Honestly It might be your Mobo but it isnt exactly dying on you. Try removing the Mobo and clean it with a brush or so and No damn water I beg of you (Obviously) and make sure to carefully dust the PCI-e slots too and then tell me if it still persists =D

 

[Ulldott]

I was just checking on my phone, and somehow accidentally selected your answer as the best solution and can't undo it :L
Oh, and the whole PC is pretty much dust free..

 

[T3CHN0RRI5]

I was just checking on my phone, and somehow accidentally selected your answer as the best solution and can't undo it :L
Oh, and the whole PC is pretty much dust free..

Haha No Probs =D Mostly it is Dust that causes probs like these.Btw What Drivers are you usin are they Legacy or the Certified ones? Try Downgrading or Upgrading them Drivers and Ht me back up =D

 

[Ulldott]

I was just checking on my phone, and somehow accidentally selected your answer as the best solution and can't undo it :L
Oh, and the whole PC is pretty much dust free..

Haha No Probs =D Mostly it is Dust that causes probs like these.Btw What Drivers are you usin are they Legacy or the Certified ones? Try Downgrading or Upgrading them Drivers and Ht me back up =D

Got my drivers from
http://support.amd.com/en-us/download and http://www.gigabyte.com/products/product-page.aspx?pid=3853#dl
Problem persists with the different drivers for 6950 and 7950. And I've tried blow away dust, but there's is hardly any in the first place, and I have a brush, but it's the most static thing in the universe so I'm not using that... 99% sure this isn't related to dust or software.

 

[T3CHN0RRI5]

I was just checking on my phone, and somehow accidentally selected your answer as the best solution and can't undo it :L
Oh, and the whole PC is pretty much dust free..

Haha No Probs =D Mostly it is Dust that causes probs like these.Btw What Drivers are you usin are they Legacy or the Certified ones? Try Downgrading or Upgrading them Drivers and Ht me back up =D

Got my drivers from
http://support.amd.com/en-us/download and http://www.gigabyte.com/products/product-page.aspx?pid=3853#dl
Problem persists with the different drivers for 6950 and 7950. And I've tried blow away dust, but there's is hardly any in the first place, and I have a brush, but it's the most static thing in the universe so I'm not using that... 99% sure this isn't related to dust or software.

This is indeed very peculiar. Try to maybe install your GPU on a friends PC and check if its still happening. Also how old is your Graphics card? If it's new it might've been a faulty one.

 

[Ulldott]

This is indeed very peculiar. Try to maybe install your GPU on a friends PC and check if its still happening. Also how old is your Graphics card? If it's new it might've been a faulty one.

Everything except the case was bought in late 2011 or early 2012 including my 6950, so it's not exactly new. The 7950 I borrowed from a friend is a few years younger. No idea about the 6570 which I borrowed from another friend, but the crashes kept happening with all 3 cards, so I don't see how it could be a faulty GPU. But today I removed everything except mobo, psu and cpu+heatsink+fan, and did some beep code testing. I don't have one of those fancy 7seg displays, so I have to stick to the beep-speaker, but the mobo was able to recognize missing ram, and passer all the tests.. Also used my brush on the PCIe slot. I took a closer look and 2 of those tiny little holes had dust in them. Re-cabled and it looks nice. Gonna try a game now and see if I still get the problems.

Update: Ok, about 30 minutes into a game, I started getting artifacts, but the game kept running this time.
This https://gyazo.com/ebf2c19fcec72eb4cfacfae730b8204f.jpg is what is looks like right now as I'm typing this. If I reboot, it will be just fine with no artifacts until I play a game again. And remember this happens with any of the 3 GPUs I have. And every time after this problem occurs and I try to open the video driver, this happens https://i.gyazo.com/46aeddc50a616aa3cface0c8f0a3597b.png

 

[T3CHN0RRI5]

This is indeed very peculiar. Try to maybe install your GPU on a friends PC and check if its still happening. Also how old is your Graphics card? If it's new it might've been a faulty one.

Everything except the case was bought in late 2011 or early 2012 including my 6950, so it's not exactly new. The 7950 I borrowed from a friend is a few years younger. No idea about the 6570 which I borrowed from another friend, but the crashes kept happening with all 3 cards, so I don't see how it could be a faulty GPU. But today I removed everything except mobo, psu and cpu+heatsink+fan, and did some beep code testing. I don't have one of those fancy 7seg displays, so I have to stick to the beep-speaker, but the mobo was able to recognize missing ram, and passer all the tests.. Also used my brush on the PCIe slot. I took a closer look and 2 of those tiny little holes had dust in them. Re-cabled and it looks nice. Gonna try a game now and see if I still get the problems.

Update: Ok, about 30 minutes into a game, I started getting artifacts, but the game kept running this time.
This https://gyazo.com/ebf2c19fcec72eb4cfacfae730b8204f.jpg is what is looks like right now as I'm typing this. If I reboot, it will be just fine with no artifacts until I play a game again. And remember this happens with any of the 3 GPUs I have. And every time after this problem occurs and I try to open the video driver, this happens https://i.gyazo.com/46aeddc50a616aa3cface0c8f0a3597b.png

Are you Overclocking it man? I mean any of your PC comps?