Im having a problem with an AR6400. After a nose dive into the dirt (my Champ copy) the left onboard servo has been malfunctioning. What it does is that servo motor keeps pushing the control rod tab toward the end of the slot, without any input from me. It doesn't stay centered at all and wont respond to any commands from the TX. When the battery is unplugged I can turn the large gear and the tab moves easily up and down the slot. When I took off the large gear and plugged in the battery the servo motor goes full tilt without input. Id be curious to know if there is a fix for this, if not Im seriously thinking of cutting the wires that lead to the servo and using plug in servos on my next project.