Question My pc booted up after installing new motherboard and cpu. Now I have a black screen. What do I do?

Aug 27, 2020
Today I finally got a new motherboard and cpu. I took out my old ones and succesfully put in the new ones. When I booted it up for the first time it turned on for five seconds, shut down on its own and restarted after like two seconds. After this happened I switched the power off on the back of the pc because I feared it would happen more and damage my pc. A couple of minutes later i switched the pc back on again.

This time it sent me to the UEFI Bios menu. I didn't really have a clue what to do there so I looked up some forums and videos to see what to do there. I didn't learn much from that but I saw that the UEFI thing recognised my hard drive and the speed of my fans.

I thougt it was a good sign that it recognised some of my hardware so I pressed save and exit on the bottom of the menu. After I did this my pc started booting up.

I was so happy when I saw my background and it asked for my password. I entered it and it was like my pc was booting up like it always did. A minute later a thing popped up saying that motherboard drivers are being installed. I also want to add that steam, discord and spotify were booting up on start, just like always.

I was thinking to myself that I got really lucky that my pc was booting up just like that, after reading many posts on different forums online of people struggling really hard with similar issues.
After the motherboard driver install was done my pc started restarting on its own, nothing out of the ordinary. Now it has restarted but my monitors are getting no signal, while they were working litterally a minute ago. I tried pulling the HDMI cable out of my graphics card directly into the motherboard, nothing.

Right now I am sitting looking at my pc that is turned on, the fans are working and it is making sounds and both my screens are black.

I'm really at a loss here.
Can anyone help me?

I also want to add my pc specifications in case it could be helpful.
Graphics card: Nvidia GeForce 2070 Super
CPU: Intel i7 9700K
Motherboard: ASUS Prime Z390-P
Power supply: Corsair VS650
Hard Drive: Seagate 1tb HDD