Screen shuts down during game play while PC is still running (Restart required)

[loveinthespace]

I need an expert to solve my problem which is
Screen shuts down while playing games, very randomly, all in a sudden, and what I have to do to make it on again, is to restart the PC, it shuts down like if the PC gave it a shutdown order (Just like when you attempt to shut down your PC) But the blue LED of screen is still on (Which means it has power), and the PC itself is all running (CPU, GPU, Mobo, all fans...) PSU is giving them all the necessary power to be running just fine..
I have checked my CPU, opened it and cleaned it all from all dust and replaced the old thermal paste with a new one, I always clean my PC from any dust using a blower, I am also taking a very good care of it.
I tried to install and see if this problem happens in Windows 7, it did happen. I am now on Windows 8, I did try to re-install Windows many times, still with no luck. I replaced the DVI cable which connects to the monitor with a VGA one, still the black out happened. I don't think it's the monitor or cable at all, it's something with the data sent to this monitor, because it cuts off during game play, I sat and thought of inserting the GPU to the other PCI-E 16_2 socket, same issue..
I updated my BIOS, I tried many graphic drivers! all the same!!! What a shame, I need help here, what am I missing?
I am playing League of Legends nowadays, and this happens very randomly 3-4 times daily, which makes me sick to my stomach to restart and then login fast to continue in order not to get suspended due to inactivity/LeaverBuster stuff...
I also played Tomb Raider, it happened just once, which is weird, how come it happened just one time in that game? There must be something with my PC anyway.
Metro Last Light: it happened like crazy...

Here are my PC specs:
AMD FX 8150 8 cores Black Edition
8 GB G Skill Ares 1600 MHz
AMD Sapphire 7870 2 GB Overclock Edition (And no, it's not overclocked, never tried to)
1 TB WD Caviar Black 7400 rpm
Windows 8 Enterprise 64 bit (with the latest updates)
Samsung 23" SyncMaster SA300 Monitor
Gigabyte 990FXA-UD3 Motherboard
Thermaltake chassis (Cool temp) Thermaltake 850 watt PSU
I am using an Asus Xonar U3 audio card (Disabled the on-board audio in BIOS)

 

[clutchc]

The usual suspects when a PC shuts down unexpectedly, is a failing or too-small PSU, or a failing gfx card. Can you try a different card of the same caliber? Also check that the PSU cables are firmly in their sockets and latched. Likewise for the gfx card cable.

 

[loveinthespace]

Hi there
Thanks for answering.
PSU cables inside the chassis are tangled to reduce space, could that be the reason?
I believe my GPU is running fine along with CPU... I ran stress tests for 2 hours and nothing happened... Clearly not overheat issue.

 

[clutchc]

Tangling should hurt the current flow thru them, but if they are blocking air flow in the case that can be a problem. And if they are putting stress on the connection points.

Is the monitor shutting down or is the PC shutting down when this happens?

 

[loveinthespace]

My PC never shuts down, it's only the monitor. So should I untangle them and remove the stress?

 

[clutchc]

In the above reply, I meant to type "shouldn't" in place of "should". Tangling alone won't hurt anything as long as there isn't any stress on the connections. But if they are blocking air flow, yes. Tie them up somehow to allow air to move thru the case.

If the PC continues to run but the monitor goes black, I would suspect either the monitor is failing or the gfx card is. When this happens, can you still hear the game going on like normal?

 

[loveinthespace]

I hear a shuttering sound of the game but is very unclear, and after a couple of secs, this sound is gone. I did stress tests, but all are positive, and this problem happens with games only I guess... So I think it's not faulty screen or GPU, am I right?
Check this out:

 

[clutchc]

Since you've tried all the usual troubleshooting fixes like driver replacement, re-install of OS, etc... I'd have to consider the card or the monitor. Sometimes when the PSU is too weak or failing, that will cause a shut down of the PC or a re-boot. But that doesn't seem to be your issue. If this only happens during gaming, that would indicate that the card is the issue. If it happens during times the PC is idle or doing light duty like surfing, I would suspect the monitor.

Just looked at your pic. No problem with that. I was referring to tangled up inside the case. The backside is just what that is for.

 

[loveinthespace]

Can't I do something if the card is failing? How about the motherboard? The problem is, I have no one who has desktop PC to try his/her gfx card on, they all have laptops

 

[clutchc]

Can't I do something if the card is failing?

Do something? Like what? You can replace the card.

There is always the possibility that the problem is the MB, yes. But from the way you describe the symptoms, I feel it is the card or monitor. If your MB had video output, you could test using it. But your board is w/o video.

 

[loveinthespace]

I don't understand... Aren't stress applications like aida64 system stability tests supposed to find out if card was failing? it could do the same if the card was failing, it didn't make my screen shut down.

 

[clutchc]

I don't know about Aida, but Furmark should stress test the card if you let it run as long as it would normally take to cause the display to go dark.
http://www.ozone3d.net/benchmarks/fur/

 

[loveinthespace]

I just ran the 15 min GPU burn test and came up with a score of 35xx and 74c as max temp, it didn't crash, nor the monitor went black.

 

[clutchc]

I just ran the 15 min GPU burn test and came up with a score of 35xx and 74c as max temp, it didn't crash, nor the monitor went black.

Interesting. Would the screen go dark in 15 minutes of gaming?

 

[loveinthespace]

You know any other software that runs gpu stress tests for hours? I tried aida64 for 2 hours long and nothing happened... yes the problem should happen within 2 hours of game playing

 

[clutchc]

yes the problem should happen within 2 hours of game playing

Well, running a 15 minute stress test is hardly the same as 2 hours of gaming. That proves nothing. Run Furmark and do the "burn-in" test. You can let it run as long as you like.

 

[loveinthespace]

I changed the PSU PCI-E cable that feeds the GPU with power. Plus, I cleaned the PSU from dust for the hundred times, could this happen from dust in the PSU? or PSU overheat?

 

[loveinthespace]

Hey this is strange.... Perhaps the PSU clean up did give me a few extra hours... I played like for more 6-10 hours but at last the issue happened when playing again... Does this explain the issue is not monitor or system related, right? I dunno what's inside that PSU, and I would better not to mess with it. How to test the PSU temp? any ideas?

 

[clutchc]

There's really no way a consumer can test the PSU for failing components like a capacitor or voltage regulator. If you think it is the PSU that is the problem, about the best you can do is swap it with another of adequate capacity.

 

[loveinthespace]

I cleaned up the PSU and all my PC from dust, worked good for a couple of days then today it happened. I could hear the game sound stuttering, then it goes completely off. Could be a driver crash trying to recover?

 

[clutchc]

I doubt it. But it would be easy enough to clean up. Just run the AMD uninistall pgm and remove all traces of the gfx driver, reboot and install the new driver. http://www.softpedia.com/get/Tweak/Uninstallers/AMD-CleanUninstall-Utility.shtml

Did the PC shut down or just the game?

 

[loveinthespace]

The monitor, man.
Okay, I will try that, thanks..