Sorry to bother about this, but I cannot understand what could be wrong. I was ready for my 2 flight today on a beach (people were leaving and only a few were left). As I gave trust to take off my djp 2+ tilted immediately and fell in the sand, motors went off immediately. I had to replace one prop which had a dent, take some sand grains out of 2 motors. I then tested the motors without props, connected to laptop to see if there was some kind of anomaly. Everything seems ok. I thought maybe the 10/15 miles/h breeze from the ocean could be responsible. I moved further away from water to have less breeze. ready for take off. I give some trust to test and for a split second I notice the front right propeller slowed or stopped. Now I could explain what happened before. So I gave up, I had a choice of an ocean or a 20 stories hotel to crash into. What can it be???? I cannot imagine being the motor, they look new (75 flights) and never made strange sounds. Could it be the electronic card attached at the motor? Anyone experience the same? I imagine that if this would have happened in the air probably it would have flipped and maybe recover.