Submarined Mavic Pro, How to Repair?

[NicoFrench]

Hi,
A friend of mine recently acquired a Mavic Pro from one of those as-is electronics pallet sales. He gave it to me to repair and keep. It looks like it spent some time under water as the EMC board sticker is red.

Problem?
Powers on, yellow light blinks real fast, no wifi signal, don't have RC to test connection.

Was unit in a crash?
Yes, most likely a watery one.

What have you tried so far?
Tried to connect to USB, but computer only detects a device for a split second when its powering on.

Wondering what parts I should start with in terms of replacement? I already ordered a new Core Board (still waiting for it to come in), once I replace it, will I be able to get a clearer picture via some self-check debug if there are other parts that need replacement? (ie the ESC board?)

I understand I would probably be better off spending the money on a new drone instead of replacement parts, but at this point it's turned into a test for myself to see if I can get it up and running.

Thanks!

 

[hherbson]

Hi,
A friend of mine recently acquired a Mavic Pro from one of those as-is electronics pallet sales. He gave it to me to repair and keep. It looks like it spent some time under water as the EMC board sticker is red.

Problem?
Powers on, yellow light blinks real fast, no wifi signal, don't have RC to test connection.

Was unit in a crash?
Yes, most likely a watery one.

What have you tried so far?
Tried to connect to USB, but computer only detects a device for a split second when its powering on.

Wondering what parts I should start with in terms of replacement? I already ordered a new Core Board (still waiting for it to come in), once I replace it, will I be able to get a clearer picture via some self-check debug if there are other parts that need replacement? (ie the ESC board?)

I understand I would probably be better off spending the money on a new drone instead of replacement parts, but at this point it's turned into a test for myself to see if I can get it up and running.

Thanks!

Hi Nico,

That sounds like a good project, and it may be true that you would be better off spending the money for a new one, but where's the fun in that? Even if it doesn't pan out, you will learn new things and gain experience. I don't have experience with wet Mavics, but unfortunately I do have experience with wet cell phones, wet RC cars and a wet camcorder. What can I say, I'm clumsy........

I would look at the boards closely with a magnifying glass, to see if there is any surface corrosion on the solder joints, or tin on the boards. If there is, this indicates it was wet for quite a while. I would also look inside the housing, and wipe it with a white cleanex to see if any residue comes off. Most water (except for swimming pools) is pretty dirty, and if it was submerges, there would likely be a dirty film on the inside. When you look into the camera, does it look clear inside?

A big risk with live electronics falling into water is the potential to short out and ruin sensitive components. I would also expect the bottom sonar modules to be damaged, but I'm not sure how water resistant they are. I would think the motors might be ok, since they're brushless, and the windings are lacquered. Does the gimbal move freely in all directions, and does anything happen when you try to turn the Mavic on?

I wonder if you could find a cheap wrecked Mavic on Ebay to act as a parts donor? They sometimes go cheap, with just a damaged gimbal assembly from hitting a tree or something.......

I know this doesn't apply now, but I believe there is a much better alternative when you drone goes swimming. Many recommend putting it in rice, but that takes forever to truly dry it out, allowing corrosion to set in, and there will often be a dirty film, from the dirty water that can be conductive causing problems with the ultra sensitive chips. My preferred method is put the device in a bag to keep it from drying, get some de-ionized water, or distilled water and flush it out thoroughly. If you can take it apart for better access, that's even better. Then I would follow up with flushing the whole thing with high concentration isopropyl alcohol, then put it in front of a fan to thoroughly dry it out. The alcohol will dilute the water and help it dry faster. I would wait till it's absolutely dry before connecting power. I don't know if the motor bearings are lubed or not, but it may be better to avoid putting alcohol on them.

I hope you enjoy your adventure, and I look forward to hearing how it goes.

Regards,

Kevin

 

[Mossiback]

...Powers on, yellow light blinks real fast, no wifi signal, don't have RC to test connection...

Fast yellow blinking indicates it cannot connect to the remote control. If you don't have a remote, you can try downloading Go 4 to your phone, move the switch by the SD slot to WiFi, and see if it will connect to your phone. I have not done it, but I found an informative set of instructions here: Flying the DJI Mavic Pro with Smartphone WIFI - RC Geeks Blog

 

[Flycaster]

Just be careful of the barometer sensors, they are electro mechanical, I beleive, and the mechanical part inside could be damaged/frozen/corroded.

 

[NicoFrench]

So got a new logic board and the mavic now boots up. I an error on the front left and right vision sensor and they do not seem to be functioning at all. Could this mean that I need to replace the vision sensor? Or is it more likely an issue with the ribbon cable that connects the ribbon cable to the board behind the gimbal?

 

[Mossiback]

...an error on the front left and right vision sensor and they do not seem to be functioning at all...

If that is all that is wrong, I would call it a win. I turned off my front sensors long ago.