Q: should i buy a new one?
A: Do not buy a new one, my 360 had the same problem and I called the customer line (should be on the last page of manual vol 1) they extended the warranty for this specific problem for three years after purchase (if yours is still under warranty) call them and they'll e mail with everything else you need to know. Just make sure you have your 360s serial number ready( back of console near av sockets. DO NOT SEND YOUR HARD DRIVE OR FACEPLATE.