Need some advice. Was unlucky and flew into a pole near some water. Broke some prop blades and my MP ended up under water. Picked it up after max 20 seconds. Dried it thourougly and used a hairdryer carefully to get rid of the water and moist. But it was dead. Put it in a bag of rice for a week and then tried again. Still dead. Cleaned battery contacts and Voila. It came alive. Starts up and looks like the main controllers work.

No picture from camera. Gimbal doesn't look physically damaged. But I can't anymore control the gimbals down angle from remote control. Hopefully it's a only looose cable. Is there some kind of selftest that reveals whats wrong ?

More serious is that I recieve Esc error when firing the Mavic up trying to take off. Only Esc-message. No message connected with motor issues. Oh forgot, looks like three of four motors "kicks" when I start it up.

Beside these two things my MP seems to work quite OK and after having woken it up from the dead I certainly not  am ready to give up know. I'm insured but I wan't to try to fix it.

Any suggestions ? Mats

Good day. I am sorry on what happened to your Mavic Pro. I am glad to know that you have tried to fix the drone yourself. But, just to make sure that we can check if all the parts of the drone is working properly is by sending the drone in for further evaluation. I'll be sending you the link just in case you want to send the Mavic Pro for repair ( https://repair.dji.com/repair/index ). Thank you.  

Thats an option but the link goes to a webpage in chinese ?

fansd1209e05 Posted at 2018-5-22 09:47
Thats an option but the link goes to a webpage in chinese ?

Hi, sorry for the inconvenience. Please try this link: https://www.dji.com/support. If there is anything else we can assist you with, please feel free to let us know, we're glad to help.

The general rule is that if there is significant water damage it is not worth repairing.

Send it in to DJI for analysis and repair, do not attempt to fly it in it's current state, it is irresponsible to do so and potentially dangerous to bystanders. Send it in fella don't be that person standing in a court after injuring somebody with a defective drone you knew was unsafe to fly.

Was it salt water?

Well since it won't takeoff it shouldn't be a problem. Besides that I'm not stupid. But sending it to DJI will probably end up in a higher cost than buying a new one.

But having gotten this far I find it worth the while to see if I can fix the rest. Love my drone so it feels crapoy to give up without a serious try.

The main controller boards seems working fine. So probably something's wrong with one engine. Or maybe something is blocking it.

The camera issue is probably somewhat more difficult to solve.

Never power on anything after got wet..  if it were me I would have ripped the battery out, recycled it.. then either let drone dry for a few days like 5 days.. or would have poured a entire bottle of 99.999% isopropyl on it since that displaced water and evaporates rapidly..

Powering on stuff after gets soaked will damage it more than leaving it on as it sinks and pull power from it within a minute while still on...  I learned this from repairing laptops.  Sometimes boards get wet and user can keep using it for a good while.  but if they panic shake it out pull power away then plug it in it to check it, dies quicker and more or less forever unless you can replace the damaged parts.   

Also never use a hair dryer or heat guns or air guns or anything to dry it.. pressurized Air can force moisture into semi sealed things like shielding cans, those are tight enough that non pressurized water may not deep in, but loose enough that that any pressure movement can find its way under the shielding.   


Chances are, your drone would have completely survived if you gave it time to dry out on its own without a hair drier or any help.. just pulled battery and left both alone on a shelf for a week.. but your impatience probably killed it..

Sorry to break it to you like that.

HereForTheBeer Posted at 2018-5-23 01:19
Never power on anything after got wet..  if it were me I would have ripped the battery out, recycled it.. then either let drone dry for a few days like 5 days.. or would have poured a entire bottle of 99.999% isopropyl on it since that displaced water and evaporates rapidly..

Powering on stuff after gets soaked will damage it more than leaving it on as it sinks and pull power from it within a minute while still on...  I learned this from repairing laptops.  Sometimes boards get wet and user can keep using it for a good while.  but if they panic shake it out pull power away then plug it in it to check it, dies quicker and more or less forever unless you can replace the damaged parts.   

He did say he put it in rice for a week? You are right though... using a hair dryer and then "assumed" he turned it on to try it would have killed it for sure.

OP: Sorry but your drone is now maybe good for exterior and cosmetic parts. The shell and maybe the screws are OK but the rest would be unsafe to use. Doyou have State Farm or DJI Care Refresh?

I agree with the fact of turning it on after I dried the water off. My intention was to fire it up and use it the heat it develops while hovering to dry the "intrails".

I didn't create any pressurized with the hairdryer. Was very gentle and careful.

It seems that the rice was effective since it came back to life. So the damage report for now is a dead gimble and ESC Error probably caused by one motor. It doesn't "kick" when turning the MP on. The red LED-light on the motor arm still works.

I also today upgraded the firmware without any problems.

So hopefully it isn't down for good.

This bird has become somewhat special to me since it already has survived an attack from a sea-eagle. The collision broke most of 3 prop blades. So it rapidly fell from 420 feet. I found it over one mile away thanks to the path on the map. After giving it some love, care and new prop blades it returned to be fully functional.

Thats why I want to try to save it one more time.

If that happened to me I would ask DJI what you should be doing with the drone? They may be able to provide you with the best information regarding water damage and motor problems?

davidmartingraf Posted at 2018-5-23 03:24
If that happened to me I would ask DJI what you should be doing with the drone? They may be able to provide you with the best information regarding water damage and motor problems?

Either way, it sounds like you have two scenarios: without DJI Care Refresh and having to pay for repair of drone, it's a coin flip outcome of paying close to the cost of new/refurbished Mavic Pro or paying to repair this Mavic Pro for a cost less than the replacement cost?

This guy seems determined to fly this drone again, no matter what the risk.

Well, there´s probably a third alternative. As a complement to my house insurance i added a part that in many cases cover accidental damage to own or others property and I Think it covers this accident. Haven´t checked out yet since I wanted to get this one up and running. We´ve in a way have become "pals" if you know what I mean. And the remaining technical issues doesn´t seem totally hopeless to solve. I´ve found lots of threads concerning ESC-problems and it looks like it´s solveable. The gimble neither moves or shows anything in the DJI-app so that could maybe be a harder problem to solve.

Ghostrdr. Of course I will fly it again. But where it will be repaired, by whom and at what cost is a completely different story.

I find it very hard to see why a 1000$-unit by routine must be scrapped due to ESC-failure. Perhaps it just some small object blocking the motor ? Or maybe just need to change ESC-module ?

Your crazy advice may lead to people throwing their drone into the trashcan. Completely without the need to do so.

My primary question was however if there are aany experienced Mavic-owners here who may have a clue of what to try with my drone.

Cant help with the camera,

but...
for the motor that doesnt move on initialization, unsolder  the 3 wires, then and only then test with a meter across any 2. If the motor is damaged the most likely cause will be damage to the windings, causing an open circuit.  You might know already but this type of motor can be thought of as 3 coils, where  one end  of each coil  are all joined together. this is assuming the motor isnt jammed.


I should imagine there are teardown vids on you tube for drones, there certainly are for most things. Then it is down to costs and availability of circuit boards and other parts.

Good Luck

Dry rice doesn't pull out water very well. Use silica gel or as a second choice instant rice.

You've had two major crashes and you've only flown 314 metres??

No, have flown it for 12-15 hours. Haven't uploaded the logs for a long time. Started out with a Parrot some years ago.

First crash it was attacked by a large bird. Maybe an eagle. Quite common at the Swedish coast.

Second crash was a pilot error hitting a flagpole 3 feet up and then down in the water. Not much to talk about since it was my own fault.

I'm quite handy with technical stuff. That why I first want to fix. If I fail, well then I'll contact my insurance company.

Thanx YachtSman for the advice. One last question. From what you say there should be some current even if the motor isn't rotating ?

Oh, forgot one thing. I dried it very carefully after the bath. When I turned it on it beeped continously and didn't connect. Aftet a week in rice it now connects fine and no beeping.

I find it very hard to see why a 1000$-unit by routine must be scrapped due to ESC-failure. Perhaps it just some small object blocking the motor ? Or maybe just need to change ESC-module ?

DIdn't say it should be scrapped... just evaluated by someone with the expertise to determine if it could be repaired and still be safe to fly. And it's not an ESC failure. It was crashed into a pole and dunked into the water by the pilot.

Well, I have several times written that it was a pilot error. And that when I fired it up after a week in a rice bag it reports ESC-failure. I have never written that an ESC-failure caused the crash.

djiuser_2RiUU2EmIkO8 Posted at 2018-5-23 10:27
No, have flown it for 12-15 hours. Haven't uploaded the logs for a long time. Started out with a Parrot some years ago.

First crash it was attacked by a large bird. Maybe an eagle. Quite common at the Swedish coast.

No no current in motor when not rotating.

measure the Resistance between the motor wires, with the wires unsoldered ie disconnected from the board.

Possible that ESC was damaged at time of crash due to drone being powered on and water entering it.  Thus, no amount of drying would have done any good.