You should try to figure out why it failed. If the motor burned up, your control surfaces may be binding. It's easy enough to figure out if that's it by opening up the case and putting receiver battery voltage directly to the leads on the motor can. Broken gears are the result of rough handling and transport most of the time. That's the problem if you can hear the motor running when you push the stick but nothing moves. If the wire got pulled out you have a wire routing/setup problem, and don't ignore that it could be at the receiver pins. A pot or circuit board failure is just random bad manufacturing which you can't do anything about, but those are amazingly rare.