Please provide me your input on this black screen problem (during gaming)

Sorry folks to bulk down the forum with more tech issues, but I just need some valuable inputs.

System:M17x R3, 680m(upgraded by myself, since may 2014)

Problem: Screen went black only and only when gaming(utilizing the gpu). The backlights are still ON, AW head logo on case still ON. I had to force reboot. This doesn't occur every time, sometimes it happens 3 times in a row then I can game fine. Next day it happens again. This also occurs when I tried alienware video shader testing. Ran alienware autopsy, all went green. F12 startup diagnostics, all went green.

Solution: Upgraded drivers with modded inf files. Reflashed bios. Repasted and resit GPU. Doesn't work.
Frick, must be another dead gpu, i thought. So I switched to 580m and decided i'll just buy another one(although very pissed it doesn't last more than a year).

Problem: Same thing occurs with 580m. Screen went black when i start gaming. All autopsy and f12 diagnostics showed no issue.

Solution: ?? I still have next day AW support till 18th. But where's the fault? What to tell them on phone? And problem if they go for online system check and see all went green.

Please, anyone can point out what's the source?

 

That is strange, I assume you did a complete wipe of all Nvidia drivers using one of the sweepers to include a possible manual sweep. It seems that your driver keeps crashing under load, when you installed the 580M you went back to Dell OEM drivers and this happened again?

 

Yes i did uninstall the 680m drivers and installed the latest 580m drivers. Tried back a few hours ago and the reinstalled 580m played games just fine, complete with 78 degree throttle i despised. That got me thinking that perhaps it is the 680m hardware that went faulty..so i switch back, do the whole process. Had a frozen black screen once, rebooted then managed to had a several rounds of titanfall and contagion just now just fine..I know this won't be permanent. Guess i'll get another card and see how it pans out.

Any chances it's the mobo? Atleast i got a reason to use my last AW warranty before it dies out. My last call to them went pretty smooth(related to 580m failing, no system checks, just a phone call, they sent a tech and replace it straight away).