So, you’ve been attempting to install atvusb-creator (a patch that allows the Apple TV to perform wonders not supported by Apple) on your Apple TV. When it failed the first time you tried something creative and, well, now your Apple TV won’t boot beyond the Apple logo.
There is a way to make it work again — apart, of course, for an interpretive dance accompanied by a song of your own composition (really, what can’t dance help?)
If that doesn’t work, when your Apple TV misbehaves in this manner just unplug the unit, plug it back in, and as soon as the Apple logo appears, mash down the Menu and Minus (–) buttons on the Apple Remote. This should force the Apple TV to ask what language you’d like to use (I’d prefer Portuguese, but I suppose you’ll choose English as we don’t speak Portuguese) as well as the resolution (oh, go ahead and choose 720p, you old stick-in-the-mud).
The next screen will ask us what we’d like to do and the correct choice is Factory Restore. This returns your Apple TV to the original 1.0 software (which, I must say, is far more responsive than the 2.x software). You’ll need to reestablish the Apple TV’s relationship with your Mac by keying into iTunes the five-digit code offered by the Apple TV.
On that Apple TV you’ll now want to choose Settings -> General -> Update Software and then allow the Apple TV to download and install the update. Once that’s done, you’re free to try installing atvusb-creator once more. I might suggest that if the original USB keydrive didn’t work, you try a different one—some work, others don’t. And if that doesn’t lead to joy, try an earlier version of atvusb-creator.