Is my computer dying?

Computer problems. Specifically, those I mentioned last post and additionally, every so often the screen blinks black and then back to whatever I was doing. This blinking may be one time, or multiple times, and while it usually is quite fast, at least twice, the screen has gone blank for a full minute or so. (Nothing particular to trigger it, either. It's happened while using Chrome in general, while looking at pics on facebook, and while attempting to watch something on VLC player.)

Zach is convinced it's something to do with the graphics card, which makes sense, only neither of us can figure out how to fix things.

Ideas? Should I be backing up everything (else; I've already backed up writing) and looking into a new computer? :/

Any and all help is much appreciated.