I received a second model …. this time all motors are ok but …. after flew it 30s that all (with a radio drop out at the end)….. I bound it after two or three more times without probem. This morning, it’s different story: I noticed, the receiver is no more binding… I didn’t nothing special… just unpluged and repluged the battery :(. My intuition is the problem comes from more the voltage regulation part burning very fast. Maybe because the actual FrSky receiver draws too much current …. Anyway, I reported the problem to Banggood …. so clearly avoid this machine until the design will be fixed.