Q: Apple TV not working

Try a restore.

Apple TV (2nd and 3rd generation): Restoring your Apple TV - Apple Support

It's possible that your USB cable is for power only. Some are. You need one that will transfer data.

This same identical thing happened to me today as well. I connected the Apple TV to my desktop computer with the "Data transferring micro USB cable" and it did the total restore to it. Yes it took a good 30+ minutes but, that is much better than needing to purchase another Apple TV. Once connected to the Big Screen TV again, it was just like plugging it in for the first time out of the box from the store. Annoying that I had to reload all my info again but, like I said, I'd rather do that than have to buy a new one.

Thanks Urban Shocker!

I woke up to this same problem.  There seem to be a few threads relating to this issue this morning.  What up with that?  First the iTunes debacle and now this?  Get on the ball apple.