I hope this is the right category, as the problem seems to be of Electrical nature.
Anyways, I used to have a No-Break connected to my system (specs below) and it would sometimes present an issue in which it would switch from line to battery in a manner that everything connected to it (in this case, my pc and monitor) would shut down, time passed and it became more frequent. I tested out one that my pa had on his pc which was the same model and both would present the problem in my system, but not on his. Time has passed and I simply got rid of it.
Now, almost immediately after I removed that No-Break, the current issue has started. Whenever I'm playing games or I'm running FurMark stress tests on my vga, my audio and video go off, but all of the computer's lights and cooling fans are still functional, including the graphs card. The computer's reset button proves useless, as I have to manually shut the system down by holding down power and turning it on again.
I've been asking around some forums, since I'm kind of a layman when it comes to hardware, and people told me through CPU-Z reports and some SpeedFan snapshots that the problem was with my 12V and 5V rails on my psu. I promptly changed it and ran some more tests, but, unfortunately, the problem persists. SpeedFan and CPU-Z still accuse the problem to be on these rails according to them, but since the psu is brand new, no one can put the finger on what's causing all this mess.
So now I go back to the title and ask if someone out there knows what's going on.
Thanks for your time.
OS: MS Windows 7 Ultimate 64-bit;
CPU: Intel Core 2 Quad Q9400 @ 2.66GHz;
Ram: 4,00 GB Dual-Channel DDR2;
Mobo: Gigabyte Technology Co., Ltd. G31M-ES2L (Socket 775);
Graphics Card: AMD Radeon HD 7900 Series (HIS HD 7970);
Power Supply Unit: Corsair TX750 V2.