Computer shuts down while playing games

[kuugun]

I'll get right to it. My computer shuts off when I'm playing games. No BSOD or freeze, it just turns off. It takes some time for the shut down to happen while playing a game, but it seems to happen quicker at higher graphics settings. I've been able to minimize shut downs by playing on minimal settings on some games but even then it still shuts down. It hasn't shut down like this any other time except when playing games.

I originally thought it was the PSU. I swapped it out, but the problem persisted. I also took out the graphics card and used the onboard one to see if that had any effect. Even though it took a lot longer(probably due to the lower settings), the computer eventually shut down again. I stress tested the CPU and GPU too see if they were overheating. They weren't, the CPU maxing out in the low 60C and the GPU mid 80C. I tested the memory and that checked out fine too.

I'm at the end of my rope. I suspect the problem has something to do with the motherboard, but I don't know any way of checking other than getting a new one. Any help or suggestions would be greatly appreciated.

 

[Cyberat_88]

You think the gpu is ok at 80C ? I should just let you burn it.
Let me guess, another bornwiki baby who thinks they can build a computer system.

 

[kuugun]

I should clarify, those numbers are the absolute max I got during extensive stress testing. While playing games they are significantly lower, the gpu usually sitting in the 60C-70C range while playing recent games at high to max graphics settings.

Not that it really matters, this isn't the first computer I've built. I've just gotten to the point that I'm fairly sure I know what is wrong, but I'm not sure how to confirm or fix it short of buying a new motherboard. I'd prefer to avoid that if possible since that is basically a death sentence for this computer and a sign to build a new one.

 

[ogxbmc]

if it runs stresstests w/o crashing then it might be drivers/psu/curruption/etc.
run intel burntest and furmark and if all goes well run them at the same time.
AND what are your specs/are you overclocking?

 

[kuugun]

I ran the tests, both individually and together, multiple times. Everything ran smoothly and stayed a a reasonable temperature.

I feel a little embarrassed posting the specs since it's about a 4 year old computer, haha. I've replaced the video card and power supply, but I know they aren't the problem since I've swapped them out with others and the problem persists. Under any other circumstances I would probably just build a new one, but I'm going to be short on funds for a while so I figure I might as well try and fix this computer until then.

Anyways, here are the specs on the old thing, nothing is overclocked:

Motherboard: BIOSTAR TPower N750
CPU: AMD Athlon 64 X2 6400+
Graphics: NVIDIA GeForce GTX 560 (Fermi) 1GB 256-bit GDDR5
Memory: 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
OS: Windows 7 Professional 64-bit

I would just like to say again that the only time it is ever shutting down is when I play games. I can apparently do anything else. I could run stress tests all day long, pushing my machine harder than any game could, without it shutting down. What is it about games that is making my computer shut down?

 

[Mr_____]

Have you tried testing the RAM? Games are constantly loading and unloading large amounts of memory, so it could be a possibility.

 

[kuugun]

Yes, I've tested the RAM with memtest86 overnight a few times and it never found anything wrong.

 

[Mr_____]

Hmmmmm... Not a GPU problem, not a RAM problem... I was going to ask if your PSU may be under powered, but it happened even when the GPU was out of it... Only other thing I can think of: have you tried uninstalling the graphics card's drivers?

 

[kuugun]

Yeah, I uninstalled the drivers and did a clean install. It didn't change anything. I eventually got fed up and, figuring I had nothing to lose, reformatted my hard drive and re-installed windows and everything else. Unfortunately, it didn't help and the computer still shuts down while playing games.

 

[ogxbmc]

What games do you have?

 

[ogxbmc]

http://unigine.com/products/heaven/download/
This WILL bring your gpu to its knees...
Also what hardware do you have installed.

 

[Cyberat_88]

Motherboard temps, HDD temps, voltage spikes overtime, bios reading.
CMOS Battery.

 

[Cyberat_88]

Overclocked system, BIOS, GPU, CPU, Voltage ?