Restoring a salt-water-logged P2 - Tips?

[jason]

Hi everyone, I was filming a surf session 3 days ago with my Phantom 3 pro,I lost control of it 3 metre from the surface,it went straight down to about 2 metre. I searched for it 20 minutes,still couldn't find it.so I swam to the shore and replay my activity logg on the map,so I took two points from the hills and aligned them to get a fix bearing to the reef where it went down which was about 150m out.I used the marks/bearing and swam a straight line out.I was lucky to have found it,it had snagged seaweed. I unplugged the battery and swam as quickly to the shore,there was a construction site nearby I found a barrel of fresh water and I completely submerged and shook it for 10 minutes so to kill as much salt.As I got home I filled up my bath tub with fresh water and gave it another bath for 1 hour,smoke started to come out of the battery so i safely disposes of it. I opened the phantom to bits and dried it with my air compressor,then let it to dry out the whole night with my table fan.The next day I went to buy WD 40 and sprayed the whole thing,all the circuit boards also including gimble+camera,the whole thing striped. I let it do its work,then blew compressed air to try and remove as much wd40 as I can.I noticed there was a blue liquid coming off the circuit board I imagine that is the waterproofing paint they put to seal the boards.On Monday I'm going to get circuit cleaner and spray the whole thing again just to remove the residue left from the WD 40.I'll let her dry out for a week and power her up and see the damage.There were no visible damage anywhere apart from the battery connector.I just hope nothings shorted out,any advice please?

You should have used distilled water as tap water as chemical as well. The WD 40 should have been left in the can.

 

[stanseychelles]

You should have used distilled water as tap water as chemical as well. The WD 40 should have been left in the can.

Thank you.I take water from a stream.I don't use treated water as there are chemical like you say,that night I did my outmost best to just try and save her,wd40 at 12pm was all I could get my hands on to kill the rust/salt water.bought another can of wd40 next day.She is working today I managed to save most,gimble, camera,vision sensor,GPS receiver board,everything.but I'm getting an ESC error,I hope its just the motors shorted out,help,when powered on the back motors beep but the front ones don't,I'm planing to swap front to back n see if they beep also.Ideas please?

 

[jason]

Thank you.I take water from a stream.I don't use treated water as there are chemical like you say,that night I did my outmost best to just try and save her,wd40 at 12pm was all I could get my hands on to kill the rust/salt water.bought another can of wd40 next day.She is working today I managed to save most,gimble, camera,vision sensor,GPS receiver board,everything.but I'm getting an ESC error,I hope its just the motors shorted out,help,when powered on the back motors beep but the front ones don't,I'm planing to swap front to back n see if they beep also.Ideas please?

The only why for the motor to short out is if the enamel coating on the wires rubbed off and shorted out. Have you done an advanced IMU and compass calibration since drying out the P2? If not do so and see resolves the problem.

 

[stanseychelles]

The only why for the motor to short out is if the enamel coating on the wires rubbed off and shorted out. Have you done an advanced IMU and compass calibration since drying out the P2? If not do so and see resolves the problem.

Hi Jason,thank you yes I've done IMU and calibration of aircraft, gimble and remote,I just updated the new 1.8 firmware for aircraft and 2.7 for remote.I have a phantom 3 pro,Do you think it could just be the motors.I guess it could be the enamel coating has come off with wd40 and shorted out,could that kill my ESC s also?thank you for the reply

 

[N017RW]

No, WD-40 did not damage coil insulation.

Since they are all disconnected you can OHM them out to see how the coils compare to each other as well as from motor to motor.

 

[stanseychelles]

As you can see the board is clean,I even got out the dark blue water proof coating on the board,if it works I can always re ally Q8/silicone spray to water proof it again.the next photo is when I sprayed it before with WD 40

 

[stanseychelles]

No, WD-40 did not damage coil insulation.

Since they are all disconnected you can OHM them out to see how the coils compare to each other as well as from motor to motor.

OHM?

 

[jason]

Hi Jason,thank you yes I've done IMU and calibration of aircraft, gimble and remote,I just updated the new 1.8 firmware for aircraft and 2.7 for remote.I have a phantom 3 pro,Do you think it could just be the motors.I guess it could be the enamel coating has come off with wd40 and shorted out,could that kill my ESC s also?thank you for the replyView attachment 49893

You know of course that that is no P2 and if there is a problem with an ESC chip the whole board will have to be replaced. Depending on which model you have could between $269 - $249 USD and that is cheap as they used to cost $400 USD.

 

[stanseychelles]

No, WD-40 did not damage coil insulation.

Since they are all disconnected you can OHM them out to see how the coils compare to each other as well as from motor to motor.

I cleaned the motors and bell housing,please teach me how to OHM

 

[stanseychelles]

This is the cheapest I've found so far,but I think new motors also would be better

 

[N017RW]

I cleaned the motors and bell housing,please teach me how to OHM

OHM (out) refers to measuring the resistance of the coils. Since it is close to a dead-short it will be quite low, say 2-4 Ohms maybe. What you are looking for is consistency across all of the measurements as opposed to a 'correct' value.

This can identify possible shorts if one or more reads lower than the rest or open-circuits should one read near infinity.

You need an Ohm meter or DMM and since you asked I might assume you do not have one so maybe a friend or colleague has one and the experience to measure with/for you.

 

[stanseychelles]

Thank you very helpful,learning a lot from you guys.Does all the motors of a phantom 3 make noise once you power up the aircraft? When i powered mine on only the back made the beep noise,so i cut off all motors half way from the main board and used connecting blocks to identify which is the bad motor or ESC.Today I switched the motors from their opposite and guess what no noise on start up??????? I presume one or two motors have shorted ou,so I will order 1 ccw and 1 cw and see what happens,they say its difficult to fry an ESC on the new phantom 3 unless the motor had trouble moving or got stuck,any ideas please

 

[stanseychelles]

Take a look