Did I burnout my graphics card?

I have a computer that I built about 4 years ago, with a few variously upgraded parts. The GPU is 1.5 year old Nvidia GTX 980 ti, and about 2 weeks ago I put in a Samsung 850 EVO SSD. I'm still using the original 650 watt PSU, which has been working fine.

A little bit ago I my computer started shutting down and restarting while playing a new game. It seemed like it was from overheating, but it was only during that game. Today, however, was particularly warm, about 80-85F with 60% humidity, and, while playing different game that I have played many times before, my computer shut down unexpectedly two times. After the second time it began to have trouble booting into Windows.

Right now the Windows will not boot except into safe mode. Here is a list of things I've tried to narrow down the source of the issue:

• I've run chkdsk on start up, which took approximately 30 min, most of which was hanging at 12% completion. Afterwards a chkdsk in safe mode did not detect any problems
• I've uninstalled and reinstalled the latest Nvidia drivers in safe mode.
• I've switched to integrated graphics via BIOS and it still requires safe mode (is it still possibly trying to load the Nvidia drivers?).
• I've tried booting from an older bootable HDD. This also would not boot normally only safe mode.
• I've removed my GPU to clean out the dust in the radiators and replaced it.
• The error I'm getting is 0xc000000e, with the message "a required device isn't connected or can't be accessed"
• The fans on the GPU spin when the computer starts up, but stop spinning after the windows splash screen

Right now I'm thinking my GPU might be burnt out. Does anyone know what is wrong or if there's anything else I could try to fix it?

I would start from square one.

Pulling all hardware out back to CPU, RAM, and Keyboard and minimal graphic support from integrated graphics or a PCI gard or something, 1 stick of known good RAM, along with a liveCD and try getting to a stable system. This includes ALL USB DEVICES except keyboard and mouse. (Had a powered USB hub cause issues once)

Then, add back in the components 1 by 1 until you start having the errors you describe to isolate the offending component.

The trick is you have to get to a known good configuration an they verify the integrity of each component. Admitadlly, you could probably plug all USB devices back in during one boot up, and all RAM stciks back in on another as a shortcut, but overall test and measure after getting to a good stable system.

If you cannot get a stable system on a barebones setup, then you swap RAM sticks, known good PS, known good CPU, etc one by one starting with what makes logical sense based on the evidence of how the system is responding with what components.