The GPS antenna must be plugged in and the GPS antenna must be working for the Phantom to power up. If the GPS antenna connector were to become disconnected with the motors running, would the Phantom power off, or does it stay powered on even if the GPS antenna is somehow disconnected? I had my P2V+ just fall out of the sky today. I was fortunate in that it fell from over 60 feet, but hit front down in some very soft mud. There's not any visible damage. It flipped over into a shallow puddle of water, though, so I have to let it dry out for a day or two. When I removed the top shell, it seemed like the GPS antenna connector was already disconnected. I don't see how this could happen, but I'm wondering if it did disconnect, could that be the cause of the fall? If a disconnected GPS doesn't power off the Phantom, then I must have had an ESC go bad. There's no signs of any problems inside the bird.