I put my IPod onto a speaker dock that I've used many times before with no problem. I heard a funny sound (sort of like a zzzt), and my IPod went dark and wouldn't work or charge. I reset it and it came on and played fine. But then when I tried to connect to the computer to synchronize, it went dead again. I reset it again, and again it was fine. But I can't connect it to sync and when I leave it connected to the computer, the IPod gets very warm. However, our wall charger works just fine with it. So I can play it and recharge it with the wall charger, but I can't synchronize or connect to the speakers. What's going on with it, and is it repairable?