[PC] Black Screen after Windows Logo, no hardware changes

Hi guys! I hope this is the right subreddit to ask this question.

I configured my PC myself and it worked fine until a few days ago. I have Windows 10 installed and now, after the blue windows logo flashes, all that follows is an endless cycle of "2 seconds black screen" to "No Signal", which constantly switches around. I do have an external GPU (GTX 970) and I tried using the motherboard HDMI-Port, but that just gave me no signal at all. But basically there's a signal coming from the GPU.

None of the parts are new, I've been running my System for a while now, with some parts older than the others. I can access the BIOS and I could also install ubuntu (USB Stick recognized, the menu is working). My Windows 10 HDD is also recognized in the BIOS. It is very old, though (7+ years). I also tried disconnecting all peripherals, but I still get the same problem.

I seriously don't know what it could be, since my system was working in this setup, the GPU puts out an image, BIOS is accessible and the HDD is recognized.

Any help would be greatly appreciated :)

Submitted August 30, 2017 at 04:32PM by niniox http://ift.tt/2vIL9xY