Monitor turn off and Nvidia driver stop working

[Xchowks]

Hello.
So, i got my pc about 3 years ago, and 2 years ago i added 8gb RAM and it was:

i7 2nd generation
Radeon HD 6870 1Gb
12 Gb RAM
Dell PSU 460W

But about 3 months ago my pc started giving black screens and freezing everything even Num-Lock then i needed to restart the pc. I did some research, and tried to replace the graphic cards with my old Geforce 9500 gt, it worked, my pc didn't crash any more then i tought it was a GPU problem, and replaced my Radeon with a GTX 760, but after some time using, the problem returned, but this time when the black screen comes, about 1~2 seconds after the screen come back and says "nvidia display driver has stopped responding and has recovered", but some times the screen just go black and never return, but the music in the background continues.

Today i bought a new 520W Seasonic PSU (thinking it was a PSU problem) and the problem persists, i don't know what else could be, i already tried to use another monitor, another UPS, old drivers, new drivers, beta drivers, did memtests and HardDrivers tests but nothing works, i don't know what else to do.

 

[Alan Caldwell]

First of all you need to TOTALLY remove all the old drivers. Use this link.
http://www.wagnardmobile.com/DDU/
Note:
Select the respective company(i.e Nvidia or ATI) drivers to be uninstalled.
Use clean and restart option.
And then install the new drivers after rebooting.

 

[Xchowks]

I removed every display drivers with your program and installed the latest nvidia driver, but the problem remains happening. It happens more when playing games or viewing videos. I can hear the fan of the GPU turning off and on when the monitor turns black.

 

[Xchowks]

Some minutes ago i was in BIOS and the problem occurred again. So i suppose its not a driver problem?

 

[zaysk]

I'm thinking it might be the PSU, if it's still doing that after a clean install of your drivers. I'd wait for someone else to confirm my theory though.

 

[Xchowks]

But i just bought a new PSU. I'm starting to think its a CPU or a Motherboard problem? I was assuming it was a heat problem, because the problem begin to occur after some hours using the PC, but all fans are working good, CPU works at 50ºC~60ºC and GPU at 60~75ºC when playing games. The GPU and PSU are new. And i think it's not RAM, since all the tests are ok.

 

[Xchowks]

Yesterday i did IntelBurnTestV2 for 5min and the the benchmark of FurMark and nothing happened, i started the Burn-in test of FurMark and after less than 1 minute the problem happened 2 times in a row, i gave it some time and started again, after ~4min of test the problem occured two times again, i turned the pc off and started the memtest again, i let it test for almost 2 hours and went to sleep, when i woke up it seens the pc crashed, the screen was black, showing no signal, but the PC was turned on.

I'm thinking more and more it is the motherboard, the problem are the same even with both old GPU and PSU and the new ones, it happens only with powerfull GPUs, because when i used my weak Geforce 9500 gt for 2 months and a half the problem never occured.