Vibration on all motors

[PythonFly8]

Problem: Vibration on all motors
Drone: Mavic Pro (software updated), no modification, original propellers
History: Never crushed or had any physical or software issue, well until now.
Owned just by me, bought it new
Device used: iPhone 8 Plus, iOS 14.1
iPhone app: DJI GO 4 v.4.3.38(4360) - latest update
Changes from last flight: none


Last flight (day before the issue):
I flew with no problems, flying at a normal temperature around 45 min with two batteries.

The day of the issue:
The drone placed on top of a car and turned on showed magnetic interference than placed down on the surface to avoid magnetic interference.
The drone took off and started to vibrate from one motor, than from all the motors. Tried to power off and power on the drone, remote control, and mobile (quit the app and clean the memory), then I tried one more time, but the same problem, vibration in all the motors. I immediately landed the drone and cancel my day.
* I will say that maybe it was just me with the subjective side that it was: starting to vibrate from one motor first. Maybe it was from all the motors but you always concentrate on one thing.

*Video from the drone

video.MOV

drive.google.com

When I got home I tried:
- Calibrate the compass (it showed that there is a need for calibration)
- Checked the motors, propellers, gimbal for physical damage - nothing
- Put new propellers
- Replaced with a fully charged battery
- Calibrate the compass (showed for calibration the compass one more time)
- Calibrate the IMU (just in case there is something with that)
These things did not change anything.


I found a YouTube video showing what seems to happen on my Mavic Pro.
This happens on Mavic Air in cold conditions, I flew at 10-20°C and there was no wind.
DJI Mavic Air Shakes

 

[PythonFly8]

Found the solution!​

How: The problem is fixed by downgrading the firmware from the latest V01.04.0500 to the oldest V01.04.0100.

I installed DJI Assistant 2 connected the Mavic Pro with a USB cable and started to find some firmware that maybe will reset everything.
First I tried downgrading the firmware to V01.04.0400 but that didn't resolve the issue, still vibrating motors and uncontrollable. (Did not downgrade the remote controller because it didn't say it's incompatible).
Then installed the latest firmware just to see if anything goes back to normal, but that didn't happen.
I knew I had to try the oldest firmware, downgraded but now I had to downgrade the firmware on the remote controller too.
The Mavic Pro was stable and smooth when flying.
As the latest step was to upgrade the firmware (drone+rc) to the latest and calibrate the IMU and compass just to make sure everything will work as it should. I didn't had to calibrate but as I said I just like to make sure everything is good!

What was the problem? I'm not sure, maybe the strong magnetic interference on the SUV was strong that the compass and IMU messed up something and couldn't be fixed until I changed the firmware.



I hope someone will find this useful when there is a need for any reference similar to this.

Have a great day! ?