I have just replaced by phantom 2 vision case because the thing literally stopped mid flight and fell out of the sky. The only thing I can think of is that the battery became dislodged? The new cover is now back on and I just put it all back together. Sadly I am getting a green and yellow flashing light. I understand from the other sites that you should claibrate the IMU. Sadly I can't get the imu to calibrate. It goes to about 80% then stops. I waited for an hour before I gave up. Any idea welcome.