Not sure what is going on with my TX. Went out to fly and doing a radio check the rudder stick was not working. It caused the rudder to go all the way to the left with no input from the stick. When I move the stick I do not get any rudder movement at all. When I put the servo in another slot it works. Tried a different RX same thing. Bummer. Any ideas what to check- If I need to send it in, where do I send it. Thanks in advance for the help