DJI Mavic Pro Salt water damage

Heres another project and that is raise a DJI Mavic Pro Platinum from the dead!

This is a Quad that crashed landed into the sea, have no idea why but my guess would be who ever was flying it ran the battery to low to get back in time?

As you can see below quite a sorry sight.

The main bottom sensor board is very salt damaged as you can see.

This was removed and run through clean warm water and then dryed off and cleaned more with isopropyl and looks better at least now:-

The esc/imu board did not look too bad apart from a tiny bit of salt corrosion around the fets. If the motors were running when it hit the sea, they will be totally shot.

The battery connector was very green and corroded, which is what I would expect as the reaction of hitting water , especially nice conductive salt water.

2 of the motors were seized and although now freed up with some oil into bearings and windings, these would need to be stripped cleaned and new bearings.

The wifi board at the back was not too bad, slight salt deposits and the gps module was also not too bad.

The gimbal was okay on 2 of the motors but seized on 1. A bit of cleaning and oil and they are now free. The camera is sealed and hence unless connector badly corroded is prob fine.

The gimbal board though got a fair bit of corrorsion on the connectors and doubt that will work again.

The battery as expected was dead. Once apart…..

Which taking these batts apart is a royal pain in the butt!!

After removing the battery pcb totally and measuring the pack, it read 0.4 volts total.

Selected nicad on the charger and slowly at 0.1 of amp started to see if it would take any charge, it slowly rose up and once it got near 9 volts, I switched to charging the pack via the lipo setting at 0.1 amp charge rate. I left it charging with a fan blowing on the pack to keep it cool. End result was it stopped charging at 12.6volts. I had to turn off the balance charge as I was charging direct to the 3 cells.

Also on a safety note, I have a metal tin close by and also was in room all the time to keep a eye out for the pack starting to puff up and turn into a fire.

(Would not advise this unless you 100% know what you doing, once cells gone this low charging can be dangerous and dont charge at anything but min charge levels.)

Not tested the fully charged pack, but I expect the cells to fall through the floor with any kind of load.

Question I hear people ask…

Is this worth a rebuild???

Really depends on how much of the quad electronics , if any still works…

Almost certainly will need 2 user parts to make it economically viable.

As using all new parts and new battery and new controller = not worth it.

Will add posts on the journey to get this to work again….

Some other pics, more cleaning required before can test what if anything still works 😉

Well the internal fan still works 😉 Although a pic wont really show that, but hey thats the first part that works ticked off list!