The gimbal motor is overloading because something is blocking the movement of that arm or the camera. If the roll arm is bent even slightly the camera will hit the ribbon ledge and cause overloading. Send it to your nearest DJI repair facility.
Be sure the landing gear isn't broken at the leg where the screw cover came off. Sounds like the leg may be bent a little which is causing the cover to not fit properly. It should snap in after inserting the prongs into the bottom of the opening (with the drone right side up - top of the opening if it's upside down).
Thanks, I’m 82. I’ve replaced the battery in my iPhone so I’m somewhat familiar with the general process. I’ll need to fix the iPad mini when my wife isn’t playing her games - hope I can get it done before she starts having withdrawal!
In sheer frustration, I pulled out my trusty pocket knife and managed to lift the bottom of the screen slightly, but in the process, cracked the glass from the bottom to the home button. The case is open now.