(SOLVED) After installing new Graphics card, my computer turns off when I open Overwatch and some other games

[ThatsAnIssue]

I bought a new Zotac GeForce GTX 1070 AMP! Edition graphics card and set it up correctly. I uninstalled old drivers, and updated to the new one which is 382.33. No matter what I do it will not open Overwatch without turning off my PC 10 or so seconds after. It always turns off when the characters load on the home screen. It turns back on instantly and is not blowing the electrical socket as i have it plugged into a power bar with my monitors (which stay on). I tried unplugging my secondary monitor and running it, I even tried updating motherboard drivers. Its not overheating, as the temp of my cpu is around 35-40C, and my gpu stays at 32-35C the game isn't open long enough for it to even be a factor. I can run borderlands 1 maxed out (i'm sure that doesn't take too much but still). I'm not sure what to do please help

SPECS

OS Windows 7 Ultimate 64
CPU Intel Core i7-4770K
RAM 2x4GB DDR3 800MHz
MOBO Gigabyte z87x UD3H
GPU GeForce GTX 1070 AMP! Edition
PSU Corsair HX750 Watt 80 Gold certified

Also I am not overclocking anything

Edit:
i tried running Overwatch with lowest settings possible, (through GForce Experience) still shut down at the same timing
going to try taking the pc apart and putting it back together..

Edit 2:
after looking at the Event Viewer I saw this.
"The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly."

going to assume that this is a problem with my power supply, as i changed the 8 pin connectors and the game stayed open for longer before crashing. i had open a program that allowed me to see stats such as memory clock, and gpu core clock, which went through the roof when it stayed open for longer.
something else i noticed was that there was a weird buzzing/humming sound coming from my psu (may have just been a fan) during this time too.
not too happy with this situation

Edit 3:
hooked up another Corsair HX750 Watt 80 Gold certified PSU to my pc and it the games ran fine. seems like something went wrong or broke in my psu, going to pick up a new one tomorrow. might explain why my old graphics card died/broke months back.

 

[ThatsAnIssue]

Power supply must have broke a long time ago when my old graphics card died (maybe short circuited something). Buying a new power supply, unfortunately. Gladly i found the answer thought .

 

[divinedookie]

Is it working now after you switched the PSU?

 

[ThatsAnIssue]

Is it working now after you switched the PSU?

fortunately my brother ended up getting the same power supply so i borrowed his to try and isolate the problem, it infact did work after changing the PSU, if not i would have tried my graphics card in his PC to see if it was my graphics card, motherboard, or maybe something else.