Anyone self-repair your gimbal yet?

[Paulark]

Had a relatively minor hard landing and severed part of the PTZ cable. Got the parts in and repaired the drone, which basically involves disassembly of a large part of the body and nearly every screw removed from the gimbal. As of now, there are two disassembly videos on YouTube. One from Cambodia and one from China (that I just discovered but haven't watched.)

I was mostly successful in repairing the drone, but after start up, it positions the camera facing back into the drone and won't calibrate....most of the time. There have been four instances of me fiddling with the camera, and suddenly it snaps into the correct position and will allow me to calibrate to 100%. It then shows no error codes and seems fixed. But as soon as i power the drone off then back on, it has lost calibration and will point the camera back towards the drone again, followed by four gimbal related error codes.

What sucks is that I really can't test it accurately unless I put it all back together. So when it doesn't work, I have to take it all back apart and try another tweak. And that's really starting to wear my patience thin.

I'm currently in the process of trying different positions of lining up the three screw holes of the gimbal motors with the camera housing. Since they are equidistant from each other, I'm hopeful that if I change the housing position in relation to the motors, eventually I will find the correct alignment and it will point the camera outwards and will allow calibration.

Please comment if you have repaired your mavic 4 and have run into this issue. It's extremely annoying to know I'm 99% there but just can't seem to find that one tiny thing that's not right.

Side note: I reached out to DJI to try and speak to a technician that has worked on the mavic 4 and they basically told me to get bent. In a really nice way, of course...but still not helpful at all.

 

[Cafguy]

I was mostly successful in repairing the drone, but after start up, it positions the camera facing back into the drone and won't calibrate....most of the time. There have been four instances of me fiddling with the camera, and suddenly it snaps into the correct position and will allow me to calibrate to 100%. It then shows no error codes and seems fixed. But as soon as i power the drone off then back on, it has lost calibration and will point the camera back towards the drone again, followed by four gimbal related error codes.

Sounds like you damaged the new cable or it isnt seated correctly.

 

[Paulark]

Ya know, that's kinda what I thought, sounds like a loose connection, right? Well, maybe not. After removing the camera housing entirely, and making sure all screws that attach it to the gimbal were tight, I discovered that the pitch motor was making a loud buzzing noise and acting erratically. That's the axis that is causing the camera to point back into the drone after startup. Check out the video and let me know what you think. I'm guessing the 4 times I got it to work correctly were just dumb luck as it sure sounds like the motor is on its way out.

Pitch motor buzzing

I guess this could be caused by a damaged cable or loose connection, but I took care during installation to make sure i didn't damage it, and the connection is seated correctly. I think if I replace that pitch motor, I should be back in business. I also have the drone insured, but I'm trying to not use the nuclear option because I don't wanna get dropped...and I'm cautiously confident in my ability to repair it I found a new pitch motor for around 80 bucks.

 

[Cafguy]

Did you blow air into the gimbal when you cleaned it? you may have blown dirt into the gimbal. if you dont think the connections or cables are bad your next move would be to replace the ESC. The part is actually available but you gotta import it from China........Good luck and let me know how its going.

 

[Paulark]

Replace the ESC? I have blown out that motor with compressed air multiple times. Why wouldn't I start with replacing the buzzing pitch motor? Looking at its behavior and loudness in that video, doesn't it seem like that's the cause and at the very least, cause the camera to stick in the backward facing position? Or do they normally sound like that with nothing attached to them? Appreciate your insight if you see/hear/know something I don't!

Edit: just realized that I needed to update the permissions for that file in Google drive. You can now view it.

 

[Cafguy]

You may have to replace the motor BUT that won't fix the problem The ESC most likely will. if you are careful and use a very light breeze of air you may be able to dislodge any obstructions or dirt. If you have used compressed air then you probably may have blown dirt into the motor itself and then you would need to disassemble and clean it. I don't disassemble gimbals....they can break your wallet troubleshooting.

 

[Paulark]

That's kinda how I feel about replacing the ESC. Then it turns a moderate repair into a major surgery...and therefore likely an insurance claim. Also, I wouldn't think the ESC would be damaged by a hard landing, but if the gimbal motor is what struck the ground first, with enough force to sever part of the cable and dislodge the whole camera from its mount, it could certainly have sustained non-visible damage. Sorry, just thinking out loud.

Side note: just spoke with a drone repair guy out of New Jersey that didn't even want to give me an opinion about the buzzing motor because they haven't worked on enough of them to know what direction to steer me in.

 

[Cafguy]

hat's kinda how I feel about replacing the ESC. Then it turns a moderate repair into a major surgery

Its not easy to troubleshoot the individual components and we all end up purchasing something we didnt need. its just the way it goes when your "chasing" a problem. After a crash I always assume the ribbon cables are damaged and replace them Bad cables or loose connections can drive you NUTS! best to get new ones right off the bat..I have not seen a Mavic 4 up close lol but I know what I have seen. Was there silicone on any of the connections?...Did you replace it. Is there any heat paste touching the body components? did you re-brush a thin layer of paste back on before you re-assembled? these little things Matter with DJI Drones.
If your not quite sure and you want to be on the safe side in the future, I would say purchase the entire camera unit now while they will still import them...You can still buy parts for the Mavic 4 from China.
I know thats not cheap but you wont be getting parts for that Drone in the U.S. anymore after the year ends.

 

[Paulark]

Well now, I think the gimbal motor may be fine. Upon very close inspection, I have discovered a tiny piece broken off the lower gimbal bracket, on the opposite side of the gimbal motor. Note the jagged surface.



That is basically a stop for when the camera is rotating on the pitch axis. Because this is the part of the camera housing that meets up with it to stop rotation.



Note the shiny surface where it is clearly passing over the stop and rubbing off the finish of the metal. I looked up the lower bracket and indeed, you can clearly see a raised stop as part of the bracket. So what I've done to test the theory is build up the stop with epoxy to where I think it should live.



So now as I wait for it to dry and contemplate the meaning of life (hint: it's 42) I'm getting excited because I really think I nailed it this time. I'll sand it just a bit to form it up then give it a shot.

 

[Felix le Chat]

Well now, I think the gimbal motor may be fine. Upon very close inspection, I have discovered a tiny piece broken off the lower gimbal bracket, on the opposite side of the gimbal motor. Note the jagged surface.

View attachment 186437

That is basically a stop for when the camera is rotating on the pitch axis. Because this is the part of the camera housing that meets up with it to stop rotation.

View attachment 186439

Note the shiny surface where it is clearly passing over the stop and rubbing off the finish of the metal. I looked up the lower bracket and indeed, you can clearly see a raised stop as part of the bracket. So what I've done to test the theory is build up the stop with epoxy to where I think it should live.

View attachment 186440

So now as I wait for it to dry and contemplate the meaning of life (hint: it's 42) I'm getting excited because I really think I nailed it this time. I'll sand it just a bit to form it up then give it a shot.

So nice to see a nod in Douglas Adams direction. Best of luck with the self-build pitch stop, I admire any Heath Robinson ingenuity.

 

[Paulark]

So nice to see a nod in Douglas Adams direction. Best of luck with the self-build pitch stop, I admire any Heath Robinson ingenuity.

Haha…just practicing up for when we have to build or modify our own parts in the very near future. Thanks for your support! It’s nearly dry enough to sand and begin the rebuild.

 

[Paulark]

Well after an initial signs were encouraging and I had the camera pointed the right way woke up this morning turned it on to an IMU gimbal error and it just got progressively worse from there. Now won't even power on so I'm sure I've shorted something out. Looks like it's time to call State Farm. That's incredibly frustrating to be that close and then have it go south

 

[UAVquadman]

Well after an initial signs were encouraging and I had the camera pointed the right way woke up this morning turned it on to an IMU gimbal error and it just got progressively worse from there. Now won't even power on so I'm sure I've shorted something out. Looks like it's time to call State Farm. That's incredibly frustrating to be that close and then have it go south

The Mavic 2 drones are much easier to work on that's for sure! best of luck. after hearing this I'm going to do my best not to crash as I have no insurance on my Mavic 4 Pro drones.

 

[UAVquadman]

Sounds like you damaged the new cable or it isnt seated correctly.

you are a true expert in this forum and very helpful.

 

[Paulark]

I'm becoming more and more convinced that they are designing these drones with the intention of them not being repaired and making it nearly impossible for the owners to do so

 

[GadgetGuy]

I'm becoming more and more convinced that they are designing these drones with the intention of them not being repaired and making it nearly impossible for the owners to do so

Which is why DJI stopped repairing drones years ago, and just provided a repair estimate instead, which when paid, resulted in a brand new drone being sent out called a refurb, which had never been flown before. The returned drone was then thrown away, or sold off to third parties for parts. Their cost of manufacture is somewhere around 10-20%% of the MSRP.