Repairing from a crash

[chrisard]

My Mavic Pro suffered an crash out of a tree and into some soft mud. The camera broke loose of the gimbal and there was some mud that needed to be cleaned out. I replaced the broken gimbal mount and re attached the gimbal arm/camera. The result is an error about the gimal motor being overloaded and that maybe I left the plastic holder still behind the gimbal.

What I noticed was that when trying to calibrate the camera could look left and right but never so much as a flicker of up and down movement from the control arm. The camera still seems to work fine but since there is something wrong with the control arm, the camera "freaks out" every 45 secs or so as if trying to recalibrate, however it seemed to fly just fine despite all this.

My question is about replacement parts. I've seen just the control arm for sale, I've seen the control arm with the camera, and I've seen the whole gimbal set up including the logic board. After watching a few repair videos the install looks possible but very tedious.

Should I chance that the logic board is in tact and just replace the gimbal arm (cost about $55 dollars)
Or is it worth is to shell out another 200 bucks for the whole camera and gimbal set up?

Any thoughts are appreciated as this is my first attempt at working on my drone.

 

[Former Member]

Lets take this one step at a time. Are you getting video?

 

[chrisard]

Yes Video is good, and while I'm sure it was a terrible idea, I put the plastic gimbal holder in place and was able to fly as normal with a fixed forward camera with out the "calibration spasms"

 

[projockey]

I'm a not too knowledgable owner but you might want to look into locking that Gimbal doing damage as it most likely will keep trying to self test or set up at intervals and possibly frying the parts that are still good.
PJ.

 

[Afremont]

I suspect the ribbon cable is damaged and needs replacing. Since you have video, the rest sounds okay.

I flew mine with the clamp installed after I broke the gimbal assembly off the vibration plate. It would film, but lots of Jello and shakiness. After replacing the ribbon cable and vibration plate, it's beautiful again.

 

[Former Member]

Next step, can you take a video of what the gimbal is doing from the time you turn it on and post it up here? Try to capture sound as well. Only about a 30 second video will tell alot.

 

[chrisard]

The ribbon cable looks like a cheep repair, though a bit tricky to install (some crazy folding going on). I think changing out the ribbon requires me to take off the camera as well, again possible but looks tedious winding the cable around. I've been looking at parts and trying to decide how much work I want to do vs how much money I can spend. I've seen just the ribbon cable, just the control arm, the control arm with camera (normally from a fried drone), and then the whole set up including arm, camera, and the logic board. I'm not excited to learn how to fold the ribbon cable or take apart the arm to wind the video cable around. This has left me pricing control arms that have a camera, needless to say this jacks up the price from just buying the arm and a ribbon cable. These are my first attempts at any drone repair and installing the ribbon cable does make me nervous. I'm going to work on it tomorrow and I'll see if i can get a short video. My best guess is it needs a new ribbon cable and maybe a control arm. I'm crossing my fingers that logic board is ok as some of these parts start getting pricey.

 

[Former Member]

Good luck in your repair.

 

[Afremont]

Given what camera and gimbal assemblies cost, it's probably cheaper to send it to someone like thunderdrones and just get what needs it fixed. From the way it sounds, you're not going to like dealing with the sealant/glue stuff that holds connectors together.

 

[Pipes101]

Given what camera and gimbal assemblies cost, it's probably cheaper to send it to someone like thunderdrones and just get what needs it fixed. From the way it sounds, you're not going to like dealing with the sealant/glue stuff that holds connectors together.

What type of sealant do you use on those connectors?

 

[Afremont]

What type of sealant do you use on those connectors?

I didn't replace it on mine and it hasn't been a problem so far. They seat quite tightly on their own, but those kind of connectors are only meant to be reconnected a relatively small number of times. I suspect the factory uses the goop more to keep moisture out of them, but that's just speculation on my part.

 

[Former Member]

I suspect the factory uses the goop more to keep moisture out of them, but that's just speculation on my part.

It's actually called silastic and it's not meant to keep moisture out, it's to keep the solder joints and connectors glued down and able to deal with vibration at the same time. A 3oz tube of it costs $35.

As far as sealing any solder joints on the motherboard, after you finish soldering or repairing them, it's best to seal them up since they were sprayed with conformal coating from the factory to make them water and mist resistant.

 

[Former Member]

They seat quite tightly on their own, but those kind of connectors are only meant to be reconnected a relatively small number of times.

Youre right at that, install one or two times and the pins bend and break very easily.

 

[chrisard]

Two of the ribbon connectors had "goop" that I had to remove in order to take out gimbal system. I did not plan on replacing this "goop". I'm attaching a link to a very short video of the drone powering up (

). You can see the camera swivel side to side but make no up and down movement at all. The drone does not respond when attempting move the camera via controller, however the video feed is still good. I assume that the ribbon cable and most likely the gimbal arm are bad.

The ribbon cable is not very expensive but looks tedious to install, while a replacement gimbal arm would come with this ribbon already in place, this still requires a complete disassembly of the arm in order to install the camera and video feed.

My issue is I don't know how to isolate if the problem is the ribbon cable, the gimbal arm, the logic board, or a combo of all or some of these.

 

[Former Member]

My issue is I don't know how to isolate if the problem is the ribbon cable, the gimbal arm, the logic board, or a combo of all or some of these.

Trial and error, and make sure you are using quality parts or it will make you crazy.

 

[tracer bullet]

My issue is I don't know how to isolate if the problem is the ribbon cable, the gimbal arm, the logic board, or a combo of all or some of these.

Keep in mind that Thunderdrones repairs drones, and might eb able to get it going for the same or less than it costs you to throw parts at it until you find the right one. might be faster too.

Might not as well, of course, but keep it in mind.

 

[chrisard]

It's actually called silastic and it's not meant to keep moisture out, it's to keep the solder joints and connectors glued down and able to deal with vibration at the same time. A 3oz tube of it costs $35.

As far as sealing any solder joints on the motherboard, after you finish soldering or repairing them, it's best to seal them up since they were sprayed with conformal coating from the factory to make them water and mist resistant.

So lets say it's worst case and I have to replace the logic board and arm ribbon etc. I've found what claim to be official DJI parts, however it was the vision position system cable(s) that connect from the drone to the gimbal logic board that had the "silastic goop" on the connectors. There is still "gummy residue" on these connectors. Should I make attempts to remove this gummy excess (I worry about damaging the ribbon cable) and then apply a new layer of silastic, or just put more on top of old stuff or say "to heck with it" and just connect them back without the silastic.

I guess what I'm asking is it worth dropping 35 bucks to seal these connectors down with a goop I know very little about?

 

[Former Member]

Should I make attempts to remove this gummy excess (I worry about damaging the ribbon cable) and then apply a new layer of silastic, or just put more on top of old stuff or say "to heck with it" and just connect them back without the silastic.

I remove as much as I can of the silastic on both the male and female connectors because it can interfere with the connector seating evenly into the contact pins. If even 1 pin is not making contact or is vibrating, it can generate an error message and will make troubleshooting very difficult. When you are removing the goop, be very very careful of the OA sensor ribbons and connectors because they get damaged very easily. One broken pin on any connector, and youre looking at buying an entirely new part.

As far as resealing the connectors, I have seen brand new OEM DJI gimbals with tiny dabs of it on the connectors and they somehow stayed connected, but if you want to save yourself some trouble, make sure they are firmly in place if youre not going to use any type of flexible sealant.

I might be over dramatizing the process, but I have fixed so many of these things and have learned from my mistakes and hope others can learn from them too.

 

[Pipes101]

@Thunderdrones can you help me trouble shoot this!?

 

[Pipes101]

@Thunderdrones can you help me trouble shoot this!?

Time stamp at 6:30