Not sure what the guilty party was, but my computer stopped driving my monitor, so after some pointless reboots and USB fiddling I re-seated the video card and tried to turn the computer back on.

Then I saw some cool lights, fans whirring, and OH FUCK my hard drive is on fire.

I smelled some life-deleting chemicals, then, fortunately, the fire put itself out.

Now I have a dead computer (I fear it) with a bunch of suspect parts.