Solved Black Screen Reboot Problems

Black screen reboot multiple times on homemade PC

I just upgraded the GPU from an ASUS Strix R9 380X OC4G that had developed the same problem.
It started with trying to max graphics on games like DOOM, then with Playerunknown's Battlegrounds.
Black screen. Reboot. Goes to Windows 10 logon, black screen, reboot, until it went to the recovery screen. Then it started doing this every time I booted the PC up. Not even letting me get to Windows. I checked everything as well as I could and the only constant I could find was that when I would run a GPU stress test during the rare times I could get it to boot all the way up, it would reboot almost as soon as the test started. I could never find an error log to reveal anything.

Yes, I know how to find the error logs.

I have an old Gigabyte GTX-660 that I thought to try out to rule out the GPU, as that was the only 'spare' part I had available.

It worked, and the problem never happened again. SO naturally, I assumed it was the GPU. I ordered a Gigabyte AORUS GTX-1060 to replace them. Installed it, new drivers, the works.
Everything was running fine until I tried to play a game. I tried out DOOM. Game loaded, started to play, BAM. Black screen, reboot, repeat to recovery screen. Every time.

I'm posting this from safe mode and need some freaking HELP!!!

Build: ASUS ROG Crosshair V Formula-Z MOBO
AMD FX-8370 CPU
Gigabyte AORUS GTX 1060 6GB GPU
G.skill Ripjaws Z series 16GB (4x4GB) DDR3-2133 Memory
EVGA Supernova 550 G2 PSU

Everything except the old GTX-660 is only just over a year old. I do not have any idea what to do. Could it be the PSU? The MOBO? Please HELP!!

hi there and thank you for the welcome. Yes everything is plugged in correctly and I believe I should have a good enough power supply. As noted above it is an EVGA Supernova 550 watt power supply. I would figure that is decent enough. I did just find something very interesting though. Asus has its software called the AI Suite. In the AI Suite it has what are called epu tools I assume that's for energy processing if you set it to automatic you cannot play much as far as high graphic games go as soon as I set it to power saving I can run anything on Ultra. With no reboots or anything. That is entirely weird and must be something to do with the motherboard and how it situates things with the change of settings. I don't know if that makes much sense or not but that's what I found just recently.