Hi. I have DJI Phantom 2. I love it. Recently I try to fly my "old" Phantom 2, I noticed, that two engines spins much slowwer, or spin and stop. Phantom was not able to take off. I changed battery, I updated the software - same thing.
Last time I used it few months back, there was no problems. I landed gently as always.
What had happened to it?
I bought new "non DJI" battery, and that was the time when I discovered the problem. When I plugged DJI battery - problem stayed.
How to fix it? How much it would cost?
Help!

I'd suggest you to send it in for fixing. By the way, it's not recommended to use "non-DJI" battery.
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DJI Mindy Posted at 2016-11-28 14:29
I'd suggest you to send it in for fixing. By the way, it's not recommended to use "non-DJI" battery. ...

I.ve had a problem with 2 motors  (1cw & 1ccw)  thats clockwise and counter clockwise.   The motors would just jerk when I applied throttle.
I had burnt out the control boards ... just a landing and the copter tipped on it's side allowing the propellers to touch the ground.
I ordered 2 new motors and 2 control boards and repaired them myself    Works like a charm  ( also have spare motors)  any handy person who has skills to take the copter apart and soldering skills can fix for you.
Phil