Hi all, after having my phantom drop out of the sky at about 40ft for no apparent reason there were understandably a few problems. I had to replace one of the LED/engine boards inside and replace two of the motors (I actually replaced all four to keep the specs the same). However on powering it up two of the blades stutter and do not turn properly until I rev up the engines and even then one of the motors seems to turn slower than the others leading to some poor performance and almost no stabalisation. I have tried updating firmware, recalibrating etc. Video is attached. can anyone suggest what may be up. Also before anyone suggests it this looks a little like the 'screws tightened up too tight on the motor' problem however I ran the motors before I screwed them back on and they did the same thing. [vimeo]121591326[/vimeo] Any help appreciated. OIr alternatively can anyone suggest anywhere in the UK who do repairs?