Question BSOD after "Starting Windows" Screen/No Video Output

Feb 17, 2019
This is sort of a two-parter.

Some months ago while I was just browsing the web, the picture on my monitor suddenly "scrambled" (for lack of a better word) and the whole PC locked up. I did a hard reset and everything was normal up until the "Starting Windows" screen ended, after which it would BSOD and shut off (same thing when booting into safety mode). Everything to me indicated this was GPU failure, however after taking out the GPU and booting the same issue persisted. Shortly after that happened I just shelved the PC and didn't think much about it.

Fast forward a few months later to now, where I have decided to make an attempt at fixing whatever was wrong. The new problem is that there is no video output all, neither the HDMI on the GPU nor the mobo give any signal, and mobo VGA didn't work either. What's interesting is that while the PC was running and I was trying to get video it didn't shut off at all, as it would have done shortly after booting last time I tried (of course I don't know what screen it was on while I was doing this). Maybe I messed something up when I put the GPU back in? but then shouldn't the mobo video ports still work?

Like I said my first thought was GPU failure (why I chose to post in this section) but I have no idea. Where do I even begin to correct this?