Hello, did you find a solution for your problem? And what was it?
I have the exactly same problem after a crash but on my mavic the rubber things on the vibration board broke, ribbon cable broke and also the camera cable..
I have replaced the vibration board and the ribbon cable still waiting for the camera cable. But when i turn the mavic on (without the camera cable) It behaves exactly as your video shows, identically and gimbal gets hot.
I have not done anything with firmware, calibrations and so on, and the messages are gimbal motor overload, gimbal restarting. Tried to calibrate the gimbal but with no success..
Any ideas? Ordered a complete new gimbal today but it would be nice to have this one working!