I have a brand new DJI Phantom 2 Vision+. When I switch on the controller the LED comes on green, beeps twice and turns solid yellow. The manual says flashing yellow indicates low battery. So I changed the batteries, same result. Checked to make sure controller and receiver were linked, seem to be. I ran through the orientation drill and everything seemed fine. GPS was indicating 8 satellites. I tried to start the motors (without propellers) and bringing both sticks to down/center does not do anything. Any ideas of what the problem may be? Thanks!