Mini 2 water damage

Paleomanjim · Jun 7, 2021

My DJI Mini 2 crashed in a swimming pool and sank 12" deep. I was able to retrieve it within 5 minutes. Removed the battery and let it sit outside for several days in 100F temps. When I place a fresh new battery in the drone the Battery level LED's on the drone body come on immediately, but just the first and last LED lights. The center 2 LED's do not come on. When I power on the drone and the controller and DJI Fly app I do get video on the iPhone. However I cannot get the drone to connect to the controller, or run the motors. I suspect the LED indicator lights must indicate a specific issue, but am unable to find any references to it. I am asking if the #1 and #4 LED lights are an indication of a specific fault? If I know what the issue is I might be able to reset or repair the faulty component. I suspect the issue may be minor and easily repaired or reset. Any advice or tips appreciated.

DJayI · Jun 7, 2021

Curious, was it salt water?

Paleomanjim · Jun 7, 2021

DJayI said:
Curious, was it salt water?

crystal clear swimming pool with fresh water

Phantomrain.org · Jun 7, 2021

So we have found that the Mini 2 has a very weak ESC module when submerged under water, most likely your going to need a new one. The problem with that is most likely they will have to replace the board.

Phantomrain.org
Gear to fly your MINI 2 in the Rain.

DJayI · Jun 7, 2021

Paleomanjim said:
crystal clear swimming pool with fresh water

Depending on the chemicals used, I would think the pool water could be harder(corrosive) on electronics than a natural body of non-salt water, for example, chlorine.
You may want to flush the drone with some distilled water or alcohol. Followed by a little forced air.

Phantomrain.org has professional experience with dunking drones, would not surprise me to find they are correct.?

GadgetGuy · Jun 7, 2021

DJayI said:
Phantomrain.org has "professional experience" with dunking drones, would not surprise me to find they are correct.?

Indeed, he does! ?
Hope the OP has DJI Care!

SkyeHigh · Jun 7, 2021

The manual shows no reference to only LEDs 1 & 4 active together. What happens if you check the battery status without plugging into the aircraft?

Paleomanjim · Jun 8, 2021

Thanks everyone. The ESC does seem like the likely cause. I have flown RC planes through sprinklers and had the ESC fail in flight but they always dry out and work later. Looked at some Youtube videos, sometimes ESC failure can be fixed by just removing the connector, cleaning and reattaching. Fairly easy to do so I'll try that today. New ESC's are available from $39 to $65 so not too expensive to fix. Some soldering involved but looks easy enough. I did purchase a used back up Combo unit locally for half price a few days ago since we are going on a cross country camping trip later this month and gotta have the Mini 2! I only had the one battery before so now I have 4 which is nice. I'll repoprt back if I get it fixed.

SpitFire · Jun 8, 2021

Wish you well in repairing the ESC issue. The Electronic Speed Controller
The ECS controls the speed of the motors, the inflight directional changes.
Most of the time hardware is damaged during a hard landing, or crash, that is when pilots receive a ESC status error. I know if a ESC board is damaged, you will need to send your drone into a repair centre, unless you have experience soldering and repairing electronics. Would appreciate feed back
on how you fixed it, since its a water issue.

Paleomanjim · Jun 8, 2021

SpitFire said:
Wish you well in repairing the ESC issue. The Electronic Speed Controller
The ECS controls the speed of the motors, the inflight directional changes.
Most of the time hardware is damaged during a hard landing, or crash, that is when pilots receive a ESC status error. I know if a ESC board is damaged, you will need to send your drone into a repair centre, unless you have experience soldering and repairing electronics. Would appreciate feed back
on how you fixed it, since its a water issue.

I spent a couple hours today dissambling the drone to repair or replace the ESC. I found the dissambly fairly easy but just to be sure I like to video everything so that re-assembly goes smoother in case I forget something. I actually found a lot more mineral deposits on the ESC than I had expected. I used alcohol to clean the boards and remove minerals. Also cleaned the Flight control board and I might clean that a bit more later. So far the problem remains, but I will likely replace the ESC board since it looks to be very easy and the cost is only $40 for a new ESC. I'm still not sure if that is the problem, any thoughts? The Flight Controller is $140 and I'm guessing that could be the issue as well. Here is the video of todays tear down.

SpitFire · Jun 9, 2021

Nice video, did not watch the whole video, saved it to watch later.
No other thoughts, I am learning from you.

Paleomanjim · Jun 10, 2021

SpitFire said:
Nice video, did not watch the whole video, saved it to watch later.
No other thoughts, I am learning from you.

Thanks. I picked up new original DJI Mini 2 ESC on Ebay for $27 shipped. At this point I think it is around a 50% chance of success, so kind of a gamble with good odds! Should be able to replace it in around 20 minutes. If it does not work others will know what not to do!

Phantomrain.org · Jun 10, 2021

Paleomanjim said:
Thanks. I picked up new original DJI Mini 2 ESC on Ebay for $27 shipped. At this point I think it is around a 50% chance of success, so kind of a gamble with good odds! Should be able to replace it in around 20 minutes. If it does not work others will know what not to do!

I hope this works out for you, without having to replace the Core board.

Phantomrain.org
Gear to fly your Mini 2 in the Rain and Land on Water.

Paleomanjim · Jun 12, 2021

Phantomrain.org said:
I hope this works out for you, without having to replace the Core board.

Phantomrain.org
Gear to fly your Mini 2 in the Rain and Land on Water.

Thanks. That why I give it a 50% chance of success, the Flight Controller board has even more electronics than the ESC!

Paleomanjim · Jun 22, 2021

Part 2 of repair attempt

Grazuncle · Jun 24, 2021

Paleomanjim said:
Part 2 of repair attempt

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Thanks for taking the time to video and upload the process.

real shame it didn't workout. I presume that battery with two LEDs is fine in your Craig's list Mini 2?

Paleomanjim · Jun 24, 2021

Grazuncle said:
Thanks for taking the time to video and upload the process.

real shame it didn't workout. I presume that battery with two LEDs is fine in your Craig's list Mini 2?

Yeah, the battery is fine, the drone has 2 LED's with any battery in it. I'm thinking the 2 LED's probably indicates what component is faulty and I contacted DJI about it but got no reply. Someone out there probably knows what it indicates so I'm hoping I might still find out. Thanks

Ian UK · Jun 27, 2021

I think the water has caused gross malfunction of the electronics, and amongst the faults are random LEDs on.
My friends drone hit the inside wall of a bridge and fell in the river, it took 2 hours to retrieve it.
It's pretty much dead. He took the covers off and flushed it with fresh water to remove debris then dried in airing cupboard. Today we flushed it with IPA. Still dead.
When you put fresh battery in, it immediately appears to power-on, there are the 3 familiar beeps, and the 4 motors twitch. No LED, no connectivity, no nothing else!
I said he should send it off to a repair centre. I'll start a new thread on this separate topic since his approach to fixing it is now to send it off to a repair shop (no DJI care package!)
I hope you get yours going, shame it wasn't the Speed Controller!

nishsailor · Jul 20, 2021

Paleomanjim said:
My DJI Mini 2 crashed in a swimming pool and sank 12" deep. I was able to retrieve it within 5 minutes. Removed the battery and let it sit outside for several days in 100F temps. When I place a fresh new battery in the drone the Battery level LED's on the drone body come on immediately, but just the first and last LED lights. The center 2 LED's do not come on. When I power on the drone and the controller and DJI Fly app I do get video on the iPhone. However I cannot get the drone to connect to the controller, or run the motors. I suspect the LED indicator lights must indicate a specific issue, but am unable to find any references to it. I am asking if the #1 and #4 LED lights are an indication of a specific fault? If I know what the issue is I might be able to reset or repair the faulty component. I suspect the issue may be minor and easily repaired or reset. Any advice or tips appreciated.

I had the same issue, fell in fresh water and dried it. Upon restarting found 1st and last led is on but the center led’s do not come on..

Paleomanjim · Jul 29, 2021

nishsailor said:
I had the same issue, fell in fresh water and dried it. Upon restarting found 1st and last led is on but the center led’s do not come on..

Yeah, at least 2 other people have got back to me to state that the #1 and #4 LED lights are on after falling into fresh water. I do think those lights are an indicator of the electrical component that is faulty. DJI never replied to my email explaining this issue. I do hope someone on here will eventually report back with info on what the problem is. I picked up a used one and am flying that but it would be nice to get the damaged one back in the air. Thanks for any info.