Hi.  I originally posted this on Mavic Pilots forums and was advised to post it here in hopes to get DJI's attention.

I've been having an issue with DJI that's going on 2 months now on getting my Mavic repaired. My Mavic keeps losing signal and the motors would shut off midair, even when it's right in front of me.

I've sent it in to DJI and DJI is declaring it user error and charging $240+ to fix it. I have disputed this with them and requested a data analysis report on why it was deemed pilot error. They said they would email me this report, but instead returned my drone unrepaired and that the case is now closed. After calling them on the phone, I was told they aren't able to release the data analysis and the case is now closed because I've received my drone. What a headache.


I was able to replicate the issue here in this video.

Uau never heard off something like this, it is frightening i can imagine 750 grams folling from the sky like a rock

Can you provide a link to the thread on MavicPilots so we can better understand what's already been discussed? And I'm guessing that someone (BudWalker?) has already looked at the DAT file, correct?

DroneFlying Posted at 2017-7-17 09:01
Can you provide a link to the thread on MavicPilots so we can better understand what's already been discussed? And I'm guessing that someone (BudWalker?) has already looked at the DAT file, correct?

Here is the link from MavicPilots.
https://mavicpilots.com/threads/ ... hut-off-video.21561

That's crazy.. they should be fixing that SMH

Wow DJI should really follow up with you. What does your screen say right before it drops?

RoyEP3 Posted at 2017-7-17 09:09
Here is the link from MavicPilots.
https://mavicpilots.com/threads/mavic-disconnects-and-motors-shut-off-video.21561

Ah, ok, that was yours. Thanks for the link and good luck.

el pelo Posted at 2017-7-17 09:18
Wow DJI should really follow up with you. What does your screen say right before it drops?

Yeah.  It was very frustrating talking to DJI on the phone and having them tell me it's "user error" and we're returning your drone can you didn't pay your invoice, without even telling me why it's user error.

What does my screen say?  I think you're referring to the "strong magnetic interference."  I don't believe this to be the reason for disconnect, and especially the motors shutting off.  The aircraft still disconnects without magnetic interference.  

RoyEP3 Posted at 2017-7-17 09:42
Yeah.  It was very frustrating talking to DJI on the phone and having them tell me it's "user error" and we're returning your drone can you didn't pay your invoice, without even telling me why it's user error.

What does my screen say?  I think you're referring to the "strong magnetic interference."  I don't believe this to be the reason for disconnect, and especially the motors shutting off.  The aircraft still disconnects without magnetic interference.

Posting here was a good call. I think you'll get significantly better service by working with one of the DJI employees.

Interesting:  The warning "Strong interference. Fly with caution." appears on your screen just as your Mavic drops. Did that appear the other times it crashed?

Gee, that hurts!

Have you tried working by elimination?

1) use a different phone?
2) fly the Mavic with RC only?
3) fly the Mavic using Wi-Fi?

Is firmware .0900 and DJI GO 4 version 4.1.3 (Android)?

Hopefully the detailed flight analysis will solve this mystery.

MARSAN Posted at 2017-7-17 10:20
Gee, that hurts!

Have you tried working by elimination?

1.  I did not try a different phone, since I know the controller and aircraft doesn't need the phone to fly.
2.  I have tried just the RC and it still loses signal.
3.  I have not tried wifi mode because I will not be flying in this mode.

The firmware it's on is V01.03.0600.  I have not updated it yet because I want to keep it on the same firmware that it was when the issue occurred, for the repair team.

RoyEP3 Posted at 2017-7-17 10:30
1.  I did not try a different phone, since I know the controller and aircraft doesn't need the phone to fly.
2.  I have tried just the RC and it still loses signal.
3.  I have not tried wifi mode because I will not be flying in this mode.

OK.

Is your Mavic physically damaged?
If not, then don't wait for DJI any longer, since you already know their reply now, and update RC and AC to the .0900 firmware (as of writing) and also use the DJI GO 4 version 4.1.3 (Android) version - as of writing.

If this works, then go and fly your Mavic now...

i for one would really like to hear dji explanation of how it is that the drone motors will stop and cause it to fall. If it is a DJI failure then with respect you owe every mavic user an explanation, not just the complainant who, if he is not scamming us absolutely deserves a proper answer. DJi if u will not provide an answer please provide a valid reason for refusing to answer. If the user is scamming DJI and the community - then tell us. If he is not scamming u or us then you really do need to explain this situation to us.

have watched the clip a number of times and i am appalled by what i see and equally appalled by how u say dji have responded. i hope you are not scamming us somehow - i do not think at all that u are. i have tended in the past to defend dji against users claiming dji fault - i definately will no longer defend them again unless i see a reasonable explanation and or proper resolution to these problems of this thread.

OK. Here we go. First you should not take off from concrete slab because they have METAL in them.

I had this happened to me once with the P4P. I took it off not even few second 5 feet up and motors shut down and fell but was lucky because we just had a foot of snow. I found out that it was the battery.

Did you try using a different battery? If not , do it, film it like you did here and let us know.

Good luck.

Bekaru Tree Posted at 2017-7-17 11:35
have watched the clip a number of times and i am appalled by what i see and equally appalled by how u say dji have responded. i hope you are not scamming us somehow - i do not think at all that u are. i have tended in the past to defend dji against users claiming dji fault - i definately will no longer defend them again unless i see a reasonable explanation and or proper resolution to these problems of this thread.

I'm not sure how this would be considered a scam.  I made sure I recorded the incident from start of flight to end, with the screen, Mavic, and pilot actions clearly visible.

I also have record of my phone call with customer service who insists it's user error, without explanation. I hesitate to share that on here because of legality, but message me if you're interested.

dronist Posted at 2017-7-17 11:48
OK. Here we go. First you should not take off from concrete slab because they have METAL in them.

I had this happened to me once with the P4P. I took it off not even few second 5 feet up and motors shut down and fell but was lucky because we just had a foot of snow. I found out that it was the battery.

I did not take off from concrete. I took off from that cardboard box.  Same result taking off from dirt or hand launching. Regardless, motors should not shut off, even in your case.

I have tried three different batteries. Unfortunately, two of those flights resulted in the Mavic motors shutting down and crashing upside down, damaging both batteries as well.

RoyEP3 Posted at 2017-7-17 12:00
I'm not sure how this would be considered a scam.  I made sure I recorded the incident from start of flight to end, with the screen, Mavic, and pilot actions clearly visible.

I also have record of my phone call with customer service who insists it's user error, without explanation. I hesitate to share that on here because of legality, but message me if you're interested.

I am not sure how it could or would be a scam either - but i just wanted to make sure. U provided compelling video evidence already - no need to share anything else and risk contravening their rules. On this forum there are some dji staff who are helpful,  i hope one of them will step in to help you. you may have to exercise a bit of patience though - then they will refer to engineers (more patience) - good luck - will be following this case.

Wow, that's pretty alarming, and a pathetic response from DJI. Hope this is resolved quickly for you

Btw guys, I've forwarded this thread to higher ups and hope to get a response soon. At this point I have nothing more to add to help you out. Thanks for your patience!

Bud the cardboard box is sat on a big (probably reinforced) concrete drive, I'm not saying that's the issue but saying it's off the box isn't a good answer
I'm shocked by this also but as above if it's a faulty battery do it with each one showing each battery serial being put in and it started up, that would help you to show it happens no matter what or just a certain battery.

All that said your video is good evidence and I have no idea why dji refused to deal with it unless it has been modified or adjusted from standard not sure.
Either way landing would be bad, but motors off.......he'll no that needs some repair as very dangerous indeed.
Do the logs show any overheating etc....any motor errors ?

Are you sure a neighbor doesn't have a military grade Drone neutralizer.... does it only do it when you are on the drive ?

Take the controller out of the garage. Thats the only thing I can come up with. Good luck.

RoyEP3 Posted at 2017-7-17 12:05
I did not take off from concrete. I took off from that cardboard box.  Same result taking off from dirt or hand launching. Regardless, motors should not shut off, even in your case.

I have tried three different batteries. Unfortunately, two of those flights resulted in the Mavic motors shutting down and crashing upside down, damaging both batteries as well.

I mentioned the concrete because of the warning message you got about the interference.

Unfortunately, if you have a bad battery the motors will shut down.

I have them all, the P3,P4, MAVIC, Spark etc. and it only happened once, with dozens of batteries and hundred of flights but after that accident, I always, always let the AC hover for at least 2 minutes, keep checking the battery for any issues and then take off but in the back of my mind I am still wary about the batteries failing.

In conclusion, DJI should take responsibility for the failure of the batteries that is causing the failure of the drone and give you a brand new set.

Good luck!

I had replied your Youtube and would like to repost here, sorry for this. Could you please export the drone's flight data and remote controller data and upload it to Dropbox, then post the link here? We would love to offer a data analyzing for this case.
Here's the tutorial video for how to export the data mentioned above:
Alike with Phantom 4 to export flight data:
Remote controller data:
Thank you for your assistance.

Except hardware issue, I guess no other circumstance or any interference would result the mavic pro dropped like this and then disconnected. After the mavic pro disconnected, the LED was still on and I doubt that the battery is a real issue. Moreover, that make me think the logic to output the "Strong interference. Fly with caution." warning was Mavic Pro detected something abnormal but don't know what exactly happened. It is not necessary an actual radio/compass/GPS signal interference there.  Your take off place seem to be thin concrete slabs on top of soil only where unlikely to have metal/rebars underneath.  Concrete with rebar inside normally apply to floor slab for multi-storey building, highway, bridge... Anyway, if there is compass interference, you may not able to take off in the first place.

i see that dji Thor and Dji Joe are involved with this thread now - am happy to see that - still watching progress on this thread -
for now i will hold off on my next dji purchases before seeing how this problem is worked out

Hmmm not good at all, hopefully they replace your a drone with a brand new one!

DJI Thor Posted at 2017-7-17 19:28
I had replied your Youtube and would like to repost here, sorry for this. Could you please export the drone's flight data and remote controller data and upload it to Dropbox, then post the link here? We would love to offer a data analyzing for this case.
Here's the tutorial video for how to export the data mentioned above:
Alike with Phantom 4 to export flight data: https://www.youtube.com/watch?v=SMb1RD5pPOg&t=6s&list=PL8-vxWY64sBOmkQQJ2KWNL-uRBZsP43-r&index=3

Thank you for joining in!

Well, I may or may not have made a mistake in already sending the drone back for repair two days ago after starting a new case, so unfortunately I cannot provide that .DAT file from that flight.  I do have the .txt file saved from the DJI Go app if it helps.

Also, here is the .DAT file from the original crash due to the same issue on 04/30.  I believe it is FLY028.DAT
https://www.dropbox.com/sh/eft7j ... YQskE19xuNRHia?dl=0

If you can give any interpretation on there from what went wrong, or show that it's user error, that would be great.

The Mavic is in the hands of the repair team now.  I can provide a case number here for the DJI techs if they are able to directly coordinate with the repair team.  I know from my last experience that they will not provide me with any information, so maybe the DJI techs here can be more communicative about that.

I will keep everyone updated on its status.  Hopefully the video evidence is undisputable this time.  

I just had the same issue as you. I flew the Magic pro in the downtown park and when it rose to 60m high, it suddenly lost connection and power and just fell out of sky. Luckily it didn't hit anyone. I sent the drone back for analysis and haven't got answer yet.

plmm32 Posted at 2017-7-18 17:35
I just had the same issue as you. I flew the Magic pro in the downtown park and when it rose to 60m high, it suddenly lost connection and power and just fell out of sky. Luckily it didn't hit anyone. I sent the drone back for analysis and haven't got answer yet.

Wow.  When did they receive your drone?  Please keep us updated on what they say.

Holy cow! did this just started happening after so many flights or is this the way it came out of the box?

Lucas775 Posted at 2017-7-18 19:16
Holy cow! did this just started happening after so many flights or is this the way it came out of the box?

Great question.  It was fine out of the box.  I've never had any prior crashes.  I don't fly often, and this happened the first day after a 2 month gap in flying.  Firmware was up to date at the time of flight.   Version 0600.

RoyEP3 Posted at 2017-7-18 09:57
Thank you for joining in!

Well, I may or may not have made a mistake in already sending the drone back for repair two days ago after starting a new case, so unfortunately I cannot provide that .DAT file from that flight.  I do have the .txt file saved from the DJI Go app if it helps.

Sincerely thanks for your feedback, I'd informed this case to our engineer and will reply you once I heard from them.  Besides, I wish if you could provide the case number.

DJI Thor Posted at 2017-7-18 23:15
Sincerely thanks for your feedback, I'd informed this case to our engineer and will reply you once I heard from them.  Besides, I wish if you could provide the case number.

The first case number which rejected my warranty:
CAS-618022-P9G9Y9

I would like to know why the data analysis is showing "user error" on that case.

The current case number is:
CAS-790460-S3C3P5

Thank you!

That's pretty scary. Replying so I can follow the progress... Good luck.

RoyEP3 Posted at 2017-7-19 01:23
The first case number which rejected my warranty:
CAS-618022-P9G9Y9

All of us would like to hear the results from this. Not Cool

If I were DJI after that video I would send you a Fly more combo FREE
Not too many I would say that about but you covered all the bases

Why?
Showing you standing to the side even arms wrapped and smart enough to put a box under it to cushion the drop. Concrete, all of us have taken off from that before and you sitting on a box 18-24" maybe. Definitely would want the Mavic and maybe the RC and batteries to analyze this. But I'm a Technician that analyzes things at work after nobody else can fix. Also I never give up and figure it out, sometimes takes awhile though.

Hey Royep3 - still watching your progress.

After how many flights did this start happening? I was gonna do some filming over water at the weekend but I think I'll give it a miss now!!!

I would have to guess, from Budwalker's data, that the problem is probably due to thermal failure in a main processor input interface. Loss of input from multiple systems - RC receiver, battery, imu, esc, gps  The Mavic goes into a fail-safe motor shutdown.  


Not Battery - Note that the DAT file shows log entries several seconds after the motor shutdown.


Not magnetic interference or IMS (or VMS) - because the Mavic is stable in hover (given the windy conditions -  drift corrections are accurate).


The "Strong Interference" message is probably due to the lack of internal exchange between the RC receiver and processor.

The fact that the Mavic is flying stably  for several minutes before shutdown - no other control or environmental intervention - points to thermal failure in a component.   I presume that this scenario is repeatable and probably occurs at about the same flying time,  as the electronics warm up.

I see no indication of operator error  - only evidence of component malfunction.