Alright I have a situation, and I will post as much as possible about the computer and what I have tried already//
Motherboard: MSI 760GM-P23 FX
-BIOS Ver 17.10
-Other Updates have been done
Processor: AMD FX 8120 8-Core 3.1Ghz 16MB Total Cache
Memory: 8GB x2 DDR3 1333MHz 16GB Total
Graphics: ATI Radeon HD7950 PCI-e 3GB GDDR5 500W min.
PSU: 700W Cooler Master
Seagate 500GB HDD Sata 2 7200RPM
Thermaltake V3+ Case w/ 3 120mm case fans 1 92mm intake fan
Ok, at first the computer was first built in a smaller case with only one 80mm exhaust fan. When the computer was powered on it booted into Windows 7 HP fine. The computer would stay on for about 30 minutes then the display would lose signal, but the computer would still be running but not functioning and non-responsive. Also, I could not power it off by holding down the power button for 5 seconds or hitting the reset button. The only way to turn it off was to hit the PSU switch on the back. I did not like doing this, BTW. Anyway, when I booted the computer the next time I ran Piriform Speccy to get temps and I noticed the system temp was a little high, about 105-125 degrees F. The processor was pulling around 95-105 degrees F. So I figured maybe it was an overheating issue. I then added the fans that are currently in the newer case to the smaller case. This brought the temp down about 3-4 degrees F. The computer would stay running until I tried to play a game or something really demanding like BF3. The game would show the loading splash screen but as soon as you got into the game and started to play, display lost signal, computer stayed running, but still not responsive. I then went on to removing the video card and tried to power on the computer. The computer stayed on for about 45 min and then same thing happened. I then proceeded to upgrade the case to a bigger one to get more airflow, mainly because the video card had about a 1/2 inch clearance to the bottom of the case. I also added Artic Silver 5 to the processor as well. I rebooted the computer with the video card back in and checked Speccy. The temps were way down around 77-80 degrees F. The system temp went up to 100 degrees F a couple of times but only fluxed every so often. I ran 3DMark2 to test the graphics, it got all the way through up until the physics test but as soon as it loaded, same problem. Here is a list of what I have changed out.
I have changed the processor, I have put in a different video card, I have replaced the motherboard. All resulting in the same behavior. I ran MRI 5.1.1 to test all the hardware and it passed with flying colors. Oh and the video drivers are up to date and the OS is up to date.
So the main problem is high stress on the GPU and CPU results in a loss of signal to display, computer stays running, but is non-responsive and will only turn off with hitting the power switch in the back on the PSU.