How'd you fix it? It happened to mine this morning....... It worked out of the box, I synced it and then ran it all day to condition the battery. I then charged it via USB on my MBP. I left it plugged in overnight, and this morning.... nothing.
I tried plugging it into the wall and into my MBP, and holding down buttons.
I ended up fixing it by taking it to an Apple Store and swapping for a new one.