Mavic Pro Gimbal Part Replacement Clarification

[mavicpro66]

I bought a Mavic Pro advertised as used but perfect condition. It arrived in mint cosmetic condition but was giving the Gimbal Motor Load Too Large error. I researched it a bit and decided to replace the ribbon cable. Myself. It flys great, video is excellent, however, it fails every gimbal calibration, it will not keep a level horizon in follow mode(tilts really bad) in other words the gimbal is not functioning properly and when I power it up once it goes through it’s startup routine the camera ends up looking to the right. I am now looking at replacing the gimbal arm with the ribbon cable, flat cable and video cable in place from either eBay or Amazon. I’ve found several for around $70. In researching possible fixes I’ve had someone on a Facebook group tell me that if I use replacement parts it will never work properly because the serial numbers or something won’t be matching. Any truth in this? In my opinion sending this thing off for repairs would be cost prohibitive and I’d rather not try and sell a bird that is flawed and transfer my problems to someone else. Just trying to get myself in a flying situation.

Mavicpro66

 

[bumper]

I have a M2P, so this may not apply:

Does the camera move freely through its complete range by hand with power off? During the power up sequence, does the camera gimbal go through all the range of motion gyrations as normal?

Before going further, I'd first try doing all all the calibration procedures, hooking drone up to computer and running Assistant 2, to include IMU, and OAC cameras etc. before replacing more parts.