I was flying on about 75% drone battery at about 50' Alt about 150' horizontally from me and the lights on the drone went dark and the drone just dropped. I do not believe that the battery came out until it hit the ground, but I can't swear to that. Now when I try to start it it won't, I have 4 solid red LED's on the drone. I have it hooked to my computer and the message I get is the battery isn't an intelligent battery. It says that it is calibrated. It would seem that something would be damaged from a fall that high to the hard asphalt, but I can't tell what. I am able to get the video to record while it is on the ground, but the camera doesn't come to life and lock into place when everything is powered up. I just don't even know what or how to diagnose the problem. On DJI assistant, what is "reset BTU" and is that something that will help? Is there someplace where I can get after crash diagnosis. I bought the drone 2-3 months ago and just took it out of the box a few days ago. This was flight number 15, all others went flawlessly.