After watching CameraGuy's video about his motor apparently not turning properly, I noticed that while he was manipulating the throttle, the LED on the affected motor's ESC flashed on and off, as if it indicate an issue with the ESC/motor speed. For ages now, one of the ESCs on my Phantom hasn't had an LED show up when flying. It started after my Phantom flew away from me (pilot error in my case, not a software fault or anything) and crashed hard in a quarry about three quarters of a mile away. The body shell was damaged, and the motor has felt more "notchy" than the others since, but spins up fine and the Phantom behaves normally in flight (I've replaced the body shell, but not the motor.) The only difference is that the LED on the ESC doesn't light up at all - I just figured that the LED connections were damaged in the crash, but could it be that the ESC detects a problem with the motor or something and doesn't light up? I can't see any broken joints in the solder on the ESC board, but I'm guessing the 3 LEDs are wired in series so if one fails they all will?