Getting a P3Pro back in the Air - Gimbal Drift and Video Breakup

[TomD]

Had a crash, it cracked the shell and broke the yaw arm.

I replaced both, and resoldered a couple of the big caps that got knocked loose off the main board. I've done a pretty thorough inspection of all the boards and cables with a loupe, no other components damaged.
Also replaced the gimbal ribbon, it looked OK, but had a sharp kink in it that would probably be a future problem.

So I have it all together and the yaw is off by about 10Deg and it's laggy on recovery from CCW yaw rotation, eventually it ends up further and further CCW until it snaps back to 10Deg 'home' when I hold and move the drone.

It also has a sort of gimbal ADD, where it homes up OK, but afterwhile , sitting still, it starts drifting around, mostly in yaw, but some in elevation too. I've disconnected the signal cable from the Vision module and it still does it, but somewhat less. Is there a Accel,Gyro chip in the camera that could be damaged? (replaced?)

Also the recorded video is fine, but the phone/tablet video starts to really break up after it warms up for a little bit. I've got really good RSSI marks, almost no red bars, and very short green, blues. I cut the bandwidth to the min and that helps, but weirdly , un-plugging the USB and then plugging it back in fixes it for about 5 minutes or more.
Any Ideas? Is there something wrong with the transmitter video decoder or USB interface?

 

[Great_Lakes]

Did you calibrate the IMU after the crash? That could be your next step.

 

[Digdat0]

what brand of gimbal ribbon did you use? I've done a few and had similar symptoms with a 3rd party ribbon. When i used a DJI one it went away.

 

[TomD]

It was a DJI ribbon, in DJI packaging.
I've done several IMU and Gimbal cals, even tried the trick where you put something under one set of skids to try to 'compensate' for the yaw offset.

The wandering is the concern, think maybe one of MEMS accel/Gyro chips has gone bad. There must be one in the camera or single channel ones in each of the gimbal boards.
I've never seen a good tech teardown of the P3Pro Camera/ and Gimbal assembly.

It does it when unplugged from the main board, so the main IMU is not sending any data, but the gimbal does respond to motion , correctly until it stands still and starts drifting.