Take a 2X4 and put it through the skids to firmly anchor the bird to the ground. Take the canopy off. Spin it up. Look closely at the servos to see if anything is moving with out input from the transmitter. Try moving the sticks and try and observe the servos. See if the movement moves and matches and holds the stick input. I think this will narrow it down and at least eliminate the servo or transmitter/receiver possibility. May want to try this with the main blades removed as well. Just my 2 cents worth. (3D) the multiplication factor you use in determining the money you will need to replace broken parts. hAhA