No, I was never able to determine the root cause. When I filed Purchase Protection claim with AMEX, they said crash was due to manufacturer defect and not eligible. DJI, the manufacturer, said in their best broken English with a lovely week long delayed response to an email, that the crash was due to the fact that I used aftermarket propellers which voids the warranty as the crash was due to neglect on my part. WHAT!?!? First of all, they've never seen my quadcopter besides a picture I sent them which had the original props on it because that's all I ever had. I never had aftermarket props. Just got a response today from them saying again, final answer, they won't refund me for my purchase and have determined that my quadcopter is ineligible for repair due to use of aftermarket props. Again, I never said anything about this to them and wouldn't have as that's totally absurd and not true.