Gimbal INOP, Works on startup, any suggestions?

[joebroke]

For context I bought this at a pawn shop and can't return it. I've tried, calibrating the gimbal (fails, never gets past 0%), I've inspected the cable and reseated it on both ends (also checked for corrosion and any debris) , I've tried IMU calibration, I've tried "GimbalCalib JointCoarse" & "GimbalCalib LinearHall" commands on dji-firmware-tools. I've tried refreshing the firmware.

I've already ordered another ribbon cable but looking for suggestions while I wait. I don't see any evidence of water damage on any of the PCB's. The gimbal moves on startup and camera works fine. (although it stops in a skewed orientation) Everything else also works as expected. All axis move fine without resistance.

I have minimal experience with drones, but I am very comfortable with electronics, micro soldering and troubleshooting.

Thank You!

 

[Cafguy]

Good to know you already have the skills to open it up .
If it moves on startup but wont calibrate then you may have a cable issue. Maybe. gimbals can be very tricky to troubleshoot.
Remember! Any silicone or heat paste you may remove during your fix MUST be replaced. Its best to put a thin coating of paste over the factory stuff before you re-assemble.
Did you calibrate the IMU first?

 

[Matt W]

I’ve had plenty of people bring their drone to me to have it fixed who said their gimbal “moves” on start up. There are 3 axis; pitch, roll, yaw. You need to identify that each axis tests/gets power on startup. I often find 1 of them does not work. Could be the motor but most likely the cable. I’ve gotten bad cables from sellers before. Always buy new cables. The signal cable is the weakest link. They can look fine but are not. Mini 3/4 signal cables are notoriously bad by design. Yaw channel is always the culprit and you cannot see any damage. Only takes 1 bad wire. I haven’t had enough experience with Air 2 yet though. You say all axis move fine without resistance. Do you mean when the drone is powered on? If so, none of the motors will power on once 1 axis fails the self test. Buy a signal cable tester from Ali express. Don’t waste your money on gimbal motor test boards. They always test good even when bad. The weakness in the motors is always the hall sensors. The motor test boards test the voltages through the coils and not the hall sensors. Maybe I’m wrong but this is what I have learned through my troubleshooting. Good luck with that second cable. I agree, it is most likely that cable.