The T11TE can't charge via USB, this is why it does not look to charge when you connect it to your PC.
If the player works normally when connected to your charger but does not work when unplugged then this is usually a sign that the battery has become disconnected from the circuit board.
The only solution to this is to send it back for fixing or to fix it yourself (only do this if you know how to fix problems like this and you understand that you will invalidate your warranty). If you got this player from us and want to send it back then please open a support ticket:
http://www.mp4nation.net/support