I recently rebuilt my q500+ due to a crash. i put every thing back correctly i think, but front rotors turn but seem to be loosing rotors.
aircraft wont fly back end wants to lift off but front end seems to be going downward.
i know out experience , i rebuild couple yet, that ist essential to hook it up to the gui, here you can check all the sensors and motor behavior. you can do all kind of calibration, and set the safety flight bounderies