Did you check the wire coming from the Rx batt to the receiver to see if its not damaged? It doesn't sound like the Rx is fried if its still working with your esc. If the wiring is ok and the batt is charged then maybe a pin on the board has come loose. You may have to send it in to us to have it looked at. It is under 2 years old of course

Check those things and let me know. TTYL.
Gary F, Team Hitec.
PS you may need to put that cover on, LOL.