For some reason it stopped getting the video input. Audio plays just fine, and Vizio logo briefly appears when you first turn it on, so I know the display isn't dead. But without the video signal it's useless.
I have no idea if this is an easy fix or a hopeless one, but no one in our family is the fix-it type, so we just gave up and bought a new TV. I figure the old one is headed for electronics recycle, but if anyone wants to try to see if it's fixable you're welcome to it.
I know that electronics recycle charges a small fee for recycling ($6). I'll cover that fee for you so that you're not stuck with it if you can't fix it.