Ok i received a RMA card because i was having issues trying to SLI a 970 SC with a 970 SSC which i found out its not possible unless you use (patch  drivers) some kind of bypass which in the long run its no good.
 
Everything was working fine other than the 2nd card (The RMA one) always running at 1.225v all the time, 1st card voltage fluctuates depending the need it dont even go to 1.2 stays around 1.162v. Started playing the witcher 3 for like 3hrs on 4k and the pc went off no electricity whats o ever. Reset mobo everything and pc didnt want to turn on. GPU Temps weren't the issue.
 
Took both video cards out and put the first one and the pc booted. Test the 1st gpu and everything working normal. In the way checked the 2nd pci ex slot to narrow the problem and the same pc booted no problems. Took that video card out and put the 2nd card (RMA ONE) pc wont even try to turn on. Check the 2nd pci ex no luck. Swap PSU cables and still no luck. Put the working card on both PSU power cables and it worked fine. So i narrow it to the 2nd (RMA CARD).
 
What could  be the problem?
 
Here are some pictures i took few hrs before the card stopped working
 

Perhaps that "work-around-patch" should be avoided? Can't confirm anything, but maybe it overheated something within the card?

zGunBLADEz
I took that patch out. But that's software.
The pc won't even turn on with the RMA card connected.

Even though it is from Wikipedia...
 
http://en.wikipedia.org/wiki/Firmware
 
certain software can "bend" or modify the way the firmware in certain hardware operates. And more than likely, the software which you used made the firmware in the video card function in a way it was not designed to do. I can't be certain, but it sounds like too much voltage went to the video card.
 
 
I would definately not recommend to use that patch. Just follow that guide that shows which EVGA cards will SLI, and which ones won't. It's easier, and you have a guarantee.

zGunBLADEz
I took that patch out way before I received the RMA card. As both ssc works fine.

This is a hardware problem caused by the RMA card as when I connect to the mobo. It don't turn on. If it was the patch the card at least would go to Windows. Pc would turn on at least.

This is what I'm saying. Because of that Patch, that patch made your GPU run in a way it was not supposed to run, frying your GPU.
 
Do not use that patch in future

zGunBLADEz
No, I took OUT the differential sli patch before receiving the new card. That's why I RMA to begin with to have 2 matching card and not need to patch nothing.

OH, ok. That "morning-ADD"