My PC started glitching out like this and I don’t know how to find the cause.
Columns of red lines dominate the screen, and certain characters aren’t being displayed during startup. This happens with every operating system and every monitor. I can only get into the OS in recovery mode.
Did my CPU get fried? My motherboard? GPU? Corrupted BIOS? How can I find out?
You have nothing to lose at this point, so you can go for it. Just run a cleaning cycle on the oven afterwards to get rid of the nasty fumes.
My R9 280X died again about a year after I did this, but I got through the mining craze of 2018 with it.