I'm concerned about my power supply. A few weeks ago my EVGA GTX 1070 FTW DT fried while i was playing Dark Souls 3, for no apparent reason. I thought that maybe the power supply (Corsair RMx 750) had destroyed it. I took my 1070 out and it had a very bad burn smell coming from it, so i sent it in for replacement. I had 1 cable plugged into it, because the PSU came with two PCIe cables that had an extension on the end so it was dual 6+2 connectors on one cable. I read that it was perfectly fine to use the single cable as long as the PSU was running on a single 12V rail, which im 99% sure it is. My question is, is this really safe? did my power supply fry my card? because for the past 2 weeks ive had my old 960 plugged into my PSU and it hasn't fried it yet, but it also has a single 8 pin connector, not 2 8 pins on the same card.
EDIT:
Specs:
Mobo - Asus Z97 Pro Gamer
CPU - Intel i5 4690k @4.5ghz
Ram - 16gb (4x4) GeIL Evo Veloce @2133mhz
PSU - Corsair RMx 750
GPU (Current) MSI GTX 960 4gb, (Dead but Replacing) EVGA GTX 1070 FTW DT
HDD/SSD - WD Blue 1tb / Crucial MX300 1tb
EDIT:
Specs:
Mobo - Asus Z97 Pro Gamer
CPU - Intel i5 4690k @4.5ghz
Ram - 16gb (4x4) GeIL Evo Veloce @2133mhz
PSU - Corsair RMx 750
GPU (Current) MSI GTX 960 4gb, (Dead but Replacing) EVGA GTX 1070 FTW DT
HDD/SSD - WD Blue 1tb / Crucial MX300 1tb