Can't get into BIOS, because my screen and keyboard doesn't turn on until the Windows Logo appears.

I've build my own PC last year, and while it's a miracle that it's even running, i'm honestly too afraid to touch it again lol. I've been having issues with Windows lately however, which is why i want to do a fresh install. Here is the problem however: I can't get into my Bios.

What basically happens is i start my PC, my screen says there is no signal, kinda "turns off and on" again like 3 times or so until the Windows Logo to login appears. My Keyboard and Mouse seems to do the same.

I've tried to disable fast boot, it didn't help. I've tried the "Troubleshoot > Advanced options > UEFI Firmware Settings > Restart" method, but then my screen just stays off and can't get a signal. Does anyone has a clue what's going on here?