Hey, totally new to quads. After whacking a car, my copter's front and rear right propellors don't spin, but if I take the whole copter and move it to different angles while it's running, I can get them all to turn at one point or another. So I guess I eliminated bad motors. It's a cheapie, a JJRC H31 trainer, but I'm thinking a motion sensor is damaged? Suggestions are welcome. - Z -