I hope the above solves your problem. In case it doesn't, I know of three XTLs where the power input socket was broken. One of the legs that are soldered to the main circuit board break (perhaps when it gets kicked or something), but stay in contact most of the time. You can tell if this is your problem by wiggling the power jack while it is in place. If the power is interrupted, then the leg is probably broken and you will have to solder in a new socket.