Dji Mavic Mini into Water. Please help revive

[Flyer91]

Hello Friends this is my first post on here due to the fact I crashed my mavic mini into water. My first drone, Ive had it for about 2 months. I was filming over a pond at my apartments and tried going under a small bridge. The mavic mini started drifting sideways and I lost control crashing the side of the bridge and fell into the water. I should mention that the pond is filled with a bluish looking water. I am guessing they add some chemicals to keep it uninfected but it still looks dark. Luckily the pond is fairly shallow so I retrieved it within minutes and dried off. Washed with distilled water, dried it and put in a bowl of brown rice for 3 days. Afterwards I took it out put battery back in and attempt to turn on which it did. Drone did connect normally to the app. Camera moved around as normally when turned on and everything seemed good and normal. Camera view did show up on my dji app on the phone. This is when the abnormal stuff started to happen. First the light on the back of drone changed between yellow, green, and red for a few seconds then it stays on red as long as its on. On the app, when I try to take off, a error message shows "ESC". ESC connection error. Repairs required. Contact DJI support for assistance. (Code 30085)"

Long story short I sent to DJI and they want $320 to replace drone, batt, and controller. I will not go that route. They did not say what is wrong with it. From researching the web, I believe either the ESC board ($40) might be fried or one of the motors on the arm might be malfunctioning. Anyone who can help give me some insight is greatly appreciated. BTW i have opened the drone and looked around but I dont see anything that looks out of place but I am no expert. Ideally I would like to know what error "Code 30085" means? and also If I could get a schematic diagram for the drone or someone to point out each part would be great. I should mention that I tried downloading the DJI assistant 2 onto my computer but the drone will not connect to it. I plugg the drone via USB and nothing happens. If someone has finished reading this I commend you and appreciate it. Any Help will be good. Thanks

Attached is a screenshot of the app showing the error message.

 

[MAvic_South_Oz]

Post flight txt log, and the dat file if it’s still there (dat needs to be direct attached in reply, or uploaded to Dropbox or similar, and a link placed in reply).

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

 

[Flyer91]

I will attemp to upload flight log info tomorrow as I do not have my phone available at the moment. Thanks

 

[MAvic_South_Oz]

Any flight logs after the crash where the problems appear should give a clue to the flight analysts here.
The original flight log will give insight into what happened to your mini, it may have been an uncontrolled descent where DJI might replace under warranty, so worth doing.
It’s also good for you (and others) to know why it happened, to help avoid similar problems in future.

Sorry to say, but it has to be said.
Mid to long term after water immersion, big problems and unreliability is almost a certainty.
It’s fine electronics and corrosion over time after a ‘bath’ is almost assured.

 

[Flyer91]

Actually the crash was my fault as I panicked and got too close to the side of the Bridge. What I want to know now is what can be done or attempted to fix the drone. What is recommended to attempt to change which parts. If i can find out what the error code "30085" means it will give me a good starting point in attempting to fix it. Also if I can know the schematic diagram of the thing. I am past dealing with Dji, they will not fix or replace, and thats fine. I do plan to aquire a better drone, the Autel Evo soon, but I will hold on to this mavic mini as a side project and attempt to fix it little by little. I did enjoy having it and if I can get it fixed it would be a great drone alternative to have. Thanks for the help

 

[bumper]

You may not have flushed and rinsed the drone and battery in distilled water enough, leaving some residue from the pond water behind. Or it did not dry long or thoroughly enough. I'm sure dry rice helps some, but silica gel (desiccant) is best. If using desiccant, be sure it is either new and just unsealed, or recently charged by heating in the oven. (I have two 10 lb commercial desiccant canisters that get heated to 400 to 450 F for 2 hours to recharge. When "used up" they weigh almost 11 pounds. Back out of the oven they are 10 lbs again) - note that most fabric enclosed desiccant packs are renewed at lower temperatures of 200 to 250F.

Do not power the drone up or use the battery until it if completely dry, otherwise additional damage can occur from electrolytic corrosion.

 

[bobec231]

For next time.
Remove and trash the battery ASAP.
Check out drone-retriever.com for what to do in the event of a water event.
They have a procedure that has worked for a colleague that splashed his drone in ocean surf last summer.

 

[m80116]

I am betting that the pond water left residue behind and that anyway water is a poison itself for electronics.
A
good way to displace water (that almost everybody has) is to use..... WD40. The very name suggests it: Water Displacement 40 formula.

Personally.... I would no go for the WD40 if I had a better option, alcohol is one (ethyl or isopropyl 99° grade) is a perfectly good solution, followed by an abundant spray of deoxidant and it would still be best if you could spray it again with alcohol to displace the greasy de-oxid, suspended and dissolved particles left over.

The boards have several shields which should be cautiously taken out to have a good rinse underneath, new thermal paste must be applied (or at least to integrate some loss) and before doing that you have to be very careful w/ heat gun to warm up the glue that's holding the socket joints in place, otherwise you highly risk of breaking the connector.

Restore a Mini from a fall through water can be done... but it takes time and patience, and some material like alcohol and thermal paste. One of the errors is to restore electrical operation while the minerals residue is still in place... electricity and humidity do the rest.

For the battery: remove lateral tag and check for humidity or water. Wash it with de-oxid.

 

[Flyer91]

Thanks for all your replies and help. I will buy some alcohol (ethyl or isopropyl 99° grade) and thermal paste. Any recommendations or preferences? What do you mean by the heat gun warm up glue. Do you mean to heat up the glue and disconect the cables completely? before spraying.

I still would like to find out what this error code "30085" means and also have a schematics diagram for the drone. I am sure DJI does not want to release this info to discourage people from working on their own drones but they leave me no choice. Thanks for all the help. I will keep researching

 

[m80116]

There's two blobs of heat glue on either side of the connectors. The connectors are actually pretty easy to release from the sockets since it's push in and pull out, which can be accomplished with the help of a screwdriver used as a lever.

The problem is the glue... if the glue isn't near its melting point it makes the operation impossible, you risk of damaging the plug in ribbon cable and socket-plug.

Once you remove all the shields it would be more clear to you what components have been affected. I suggest you take the shields off and inspect the boards before rinsing with alcohol and deoxid. You may have a better chance at finding ailing components, affected by the left over residue.

 

[Flyer91]

I took the outer cover body off and everything inside looks pretty good. There seems to be a little bit of white powder buildup in one area, i point it out on the attached pictures. I will try to clean thoroughly with deoxid, brush, and q tips. Then dry with a hair dryer on low setting.

 

[Flyer91]

 

[Flyer91]

 

[JAW]

Personally, I would never trust that drone again.

 

[Flyer91]

Thanks for your input. I will also not trust this drone again. However If i do get it flying again I will take the upmost precautions when flying, never flying it over any people or areas where it can cause major damage to other or things if it falls. Mainly open parks.
I just would have it as a practice drone to sharpen my flying skills. THanks

 

[m80116]

It isn't necessary to remove the ESC board since it's quite exposed, but you should definitely take out the FC (lower) board and the IMU board. Disconnect their connectors (thoroughly warm up to glue blobs) and spray wash them clean with solution and a brush after inspection.

Water is a very capillary fluid... it takes nothing to seep underneath the shields, and it isn't easy to wash the residue out. Fingers crossed it can come back to flying!

But anyway... over water with fooled VPS and partially block satellites it's a tough challenge for a Mini. I wouldn't mind trusting a second time if it flies fine.

 

[midi459]

Hello Friends this is my first post on here due to the fact I crashed my mavic mini into water. My first drone, Ive had it for about 2 months. I was filming over a pond at my apartments and tried going under a small bridge. The mavic mini started drifting sideways and I lost control crashing the side of the bridge and fell into the water. I should mention that the pond is filled with a bluish looking water. I am guessing they add some chemicals to keep it uninfected but it still looks dark. Luckily the pond is fairly shallow so I retrieved it within minutes and dried off. Washed with distilled water, dried it and put in a bowl of brown rice for 3 days. Afterwards I took it out put battery back in and attempt to turn on which it did. Drone did connect normally to the app. Camera moved around as normally when turned on and everything seemed good and normal. Camera view did show up on my dji app on the phone. This is when the abnormal stuff started to happen. First the light on the back of drone changed between yellow, green, and red for a few seconds then it stays on red as long as its on. On the app, when I try to take off, a error message shows "ESC". ESC connection error. Repairs required. Contact DJI support for assistance. (Code 30085)"

Long story short I sent to DJI and they want $320 to replace drone, batt, and controller. I will not go that route. They did not say what is wrong with it. From researching the web, I believe either the ESC board ($40) might be fried or one of the motors on the arm might be malfunctioning. Anyone who can help give me some insight is greatly appreciated. BTW i have opened the drone and looked around but I dont see anything that looks out of place but I am no expert. Ideally I would like to know what error "Code 30085" means? and also If I could get a schematic diagram for the drone or someone to point out each part would be great. I should mention that I tried downloading the DJI assistant 2 onto my computer but the drone will not connect to it. I plugg the drone via USB and nothing happens. If someone has finished reading this I commend you and appreciate it. Any Help will be good. Thanks

Attached is a screenshot of the app showing the error message.

distilled water best idea .next would be alcohol then leave it in a nice sunny place for a week or more and remove the covers if possable ...well that beeing said ...id replace the esc ...let the battery go sit as it has a charge controller card inside it and may have fried ..alcohol absorbs water but i wouldnt dunk a lipo on it ..it just might blow up in ur face .....go order the esc and replace it the battery controller just might be finished start there and go look on the rc plane group listing and see how they trouble shoot electronics

 

[shb]

I crashed in the ocean but retrieved the drone. I cleaned and dried it. It powered on but wouldn't connect to the controller. Now, a year later, left on plastic container with rice, it's flying again. But the gimbal/camera isn't working. I ordered a new one but it hasn't come yet.

 

[Medley]

Perhaps you’ll find some hope in my recent experience with my Mavic Air. I posted a video in the Photos and Videos section telling the story...

I used lots of compressed air, but nothing else. However, I did disassemble it while it was still wet. I let it sit in that state for a week after which I used various small brushes and more compressed air to remove any dried silt that had settled in various nooks and crannies.

Good luck; I hope you are able to revive your Mini.

 

[AstroBacon]

Did you have any luck replacing the ESC board? I have this same problem. A goose attacked my drone, and it went down in a pond. It actually spent 24 hours under water before I could locate it. I took it out, tore it down, cleaned it off, and put it in rice. It powers up, connects, and everything works except the same ESC error. It's pretty resilient if that's the only problem it has. I'm impressed.