Very good job on the video.
Unfortunately, there are things in the video that are beyond my ability to diagnose with any certainty without having the camera in hand.
Some thoughts:
1.) I think the motor circuits are good. I see slight powered response to the initial bump on Yaw and pitch, and maybe also the roll. Also, the volume and tone of the beep (which comes from the motors) is normal.
2.) The long beep is normally an "alert" to make you aware the camera is about to sound a series of encoder error codes. Except two things are wrong. It comes very late. And it is not followed by the actual codes. This suggests two things. The first is that the gimbal board main processor is running much slower than normal. The second is that the board cannot properly process the errors. But these are only speculation.
The gimbal boards can be found on the internet (unfortunately) and they are easy to physically replace. This has led many to purchase them. But the new boards (or used boards from another camera) will not work. The replacement boards must be calibrated one at a time to the individual camera, and that software was never released to the public.
3.) The best bet is to contact one of the repair centers that have the actual parts/software and can do a much better diagnostic with the camera in-hand. I would recommend at least contacting
https://yuneecskins.com/all-product...mera-repair-estimate-service-cg3-cmr-rpr-stm1 via the listed e-mail to see what shipping costs might be.