Won't charge

I have had my MP3 player for going on 3 years, I have never had a problem with it. This last week I noticed that when I plug it into my computer, it turns on as usual (as if it is going to charge) and then the little battery looking icon on the bottom right hand side starts flashing from a full battery to a chargeable battery icon. I have never seen this before. And when I do unplug it and turn it on, it shows that it hasn't charged at all.
I have tried uninstalling it and installing it and all the other property checks on troubleshooting and everything seems in order.
Any ideas??