Up until now I've been very happy with my 4th generation 8GB Nano. Today, I was listening to it and all of a sudden it turned off. I tried to turn it back on, but it wouldn't. I figured I must have lost track of how much charge was left in the battery and I just needed to charge it. I plugged it into my iBook, but the Nano's screen never lit up telling me it was synchronizing. Nor did the iPod icon appear on my screen and iTunes did not open like it usually does when I connect my iPod. Any ideas as to what's wrong with it or how to fix it? Should I just take it to an Apple store and see if it can be fixed? It's obviously still under warranty.