I'm new to flying drones, and this is my first drone. It was all fun, till today.
So short after take off, it became completely unresponsive/uncontrollable, and _luckily_ crashed into tree before getting into some person / child face head..
I wrote more on someone's similar thread here :
https://forum.dji.com/forum.php?mod=viewthread&tid=187149&page=1#pid1832896

The drone just went flying left from me, fast without listenning to my controls.  Merely avoiding car which which coming in, people couldn't understand wtf I was doing ..

Here is the log:

https://www.phantomhelp.com/LogViewer/EIIVABQH9TCL90B8UQZZ/

It all looked good on the controller, not errors, GPS was green as far as I remember ..   What went wrong - compass ?

I'm a bit freaked out, and lost my full confidence in it being safe for people around me (never mind my $$).

Anything else I need to know besides always check magnetic interference  && always do compass calibration before each flight?

Yes it was compass, and looks like strong interference, can you let us know, if you calibrated compass prior to take off, did you take off near metal objects, or concrete ?

Hello v01d,  I'm sorry to know what happened to your drone. This is not what we want you to experience with DJI . Kindly contact our support team to start up a ticket : https://www.dji.com/support?site=brandsite&from=nav and send in the drone for data analysis. We have a designated team who will do their best to find out the crash reason and then the corresponding resolution would be provided. Please take note that DJI will not perform data analysis for cases occurring after the expiry of the warranty period; otherwise, valid charges will apply. Thanks for your support.

DJI Paladin Posted at 4-21 08:15
Hello v01d,  I'm sorry to know what happened to your drone. This is not what we want you to experience with DJI . Kindly contact our support team to start up a ticket : https://www.dji.com/support?site=brandsite&from=nav and send in the drone for data analysis. We have a designated team who will do their best to find out the crash reason and then the corresponding resolution would be provided. Please take note that DJI will not perform data analysis for cases occurring after the expiry of the warranty period; otherwise, valid charges will apply. Thanks for your support.

Hello DJI Paladin,

Thank you for replying.  Yes my drone is quite new, only purchased December 2018.

I also have a DJI Care Refresh Service, for 12 months, so  I plan to find one DJI center somewhere closer to me.  I want them to have a look at it, as the gimball had a crash and I had to physically adjust it back into the seating to make it work again properly.

hallmark007 Posted at 4-21 07:18
Yes it was compass, and looks like strong interference, can you let us know, if you calibrated compass prior to take off, did you take off near metal objects, or concrete ?

Hi,

Just filed in the ticket request , plan to drop it off this week. Will post on results.

About compass: I took off as soon as it said on the phone "ready" / the GPS green rectangle at the top.
I don't go through compass calibration every flight, say only first flight of the day -  on this specific day compass was calibrated easy from same village, about 500 m away from the 'bad' sport. First light was all good.

Does DJI  product manual say you have to go through compass calibration procedure every time before every flight?  If so I may have missed it, but the "manual" that came with unit was rather thin & small printed...

About metal/magnetic objects : lemme think.  And I wait for what the support  / repair guys analysis will tell me.
Dunno if I should speculate before they look at it and tell me something..
PS: Don't bother with Google maps / street view of this place ..I just saw it must be at least couple years off, the parking lot I took off from wasn't even built then ...

Questions:  Are you interested in seeing what might have caused compass error?
- Can you easily and in a reasonable amount of time, return to area (Darwin Street / Foodworks Maryville)?
- Do you know exact takeoff spot of drone?

Question: On GO-4 display, was there any yellow or red warnings?

HedgeTrimmer Posted at 4-21 19:48
Questions:  Are you interested in seeing what might have caused compass error?
- Can you easily and in a reasonable amount of time, return to area (Darwin Street / Foodworks Maryville)?
- Do you know exact takeoff spot of drone?

Answers:

I cannot easily return to that spot, as it's few hours of driving.
I remember exact spot of take off.

Next time I'm there I'll try.

HedgeTrimmer Posted at 4-21 19:48
Questions:  Are you interested in seeing what might have caused compass error?
- Can you easily and in a reasonable amount of time, return to area (Darwin Street / Foodworks Maryville)?
- Do you know exact takeoff spot of drone?

Answer on warnings:

As I wrote, before take off, there was absolutely not warnings, all was green.

But few seconds after take off, that's when all hell broke loose: error reported, etc..Exact number of errors/warnings I can't say, as my eyes were fixed on the drone, not on remote .....

Beyond this, and the log I've shared, I can't add anything more.

v01d Posted at 4-21 18:57
Hi,

Just filed in the ticket request , plan to drop it off this week. Will post on results.

Good job, and your right you shouldn’t speculate, there are procedures that can help avoid these situations, it’s not very complicated and you shouldn’t make it that way, you don’t need and shouldn’t calibrate your compass before every flight, my Mavic Pro shows excellent compass values I have only ever calibrated compass once since I’ve had it, and I have it two and a half years.

I hope your case is successful for a warranty I understand you have care refresh as a back up guarantee, so good luck, and if you need any help in learning about all this stuff I’m certain you will get it around here.

v01d Posted at 4-21 22:43
Answers:

I cannot easily return to that spot, as it's few hours of driving.

Not suggesting you try flying from there again.  Only to check spot for sources of magnetic interference.
Possibly buried metal gas pipes, electrical power, etc.

v01d Posted at 4-21 18:57
Hi,

Just filed in the ticket request , plan to drop it off this week. Will post on results.

I just saw it must be at least couple years off, the parking lot I took off from wasn't even built then ...

Parking lot cement or aspalt?   Cement parking lot, then it probably has steel mesh in cement.
Take off very close to a car, like within half a meter?

I have filed the support case, and already dropped off the drone for check / repair.  I 've referenced this thread too for my description of the issue, like the log link. Although, DJI guys probably will extract log themselves...

I accidentally walked into the "personnel only" room, and , saw tables and bunch of technicians testing / troubleshooting drones.  Also, a netted area for testing. Wow, looked like a spy/military facility , lool (for someone with big imagination .. ). Unfortunately they quickly booted me out, to the depo / receiving dept.

I mention above only that I really hope they will give me some kind of detailed report and describe what, if anything , they have fixed / troubleshooted.  Because, it's clear their system is such all communication is through the on-line DJI support ticketing system ...
I kinda naively hoped that by going to the depo myself, I will be able to explain them and mention things I haven't here .. Like that I think they should test my gimball, because it took a knock in the crash ..
And, also that my video had glitches after I flied it after the crash ...

Anyway.

HedgeTrimmer Posted at 4-22 07:44
I just saw it must be at least couple years off, the parking lot I took off from wasn't even built then ...

Parking lot cement or aspalt?   Cement parking lot, then it probably has steel mesh in cement.

If the drone already took off (like say couple of secs after), does it matter that car drove upto me at the back , close?

The parking lot is asphalt, but I'm not sure on the spot I took off from.  It could have been a cement plate, i need to check.

Won't the drone complain about compass if there is magnetic interference? I think when there is, it usually complains about it before take off - am I wrong?

v01d Posted at 4-23 01:58
If the drone already took off (like say couple of secs after), does it matter that car drove upto me at the back , close?

The parking lot is asphalt, but I'm not sure on the spot I took off from.  It could have been a cement plate, i need to check.

If the drone already took off (like say couple of secs after), does it matter that car drove upto me at the back , close?

Doubt car would cause a problem.  Unless car got within 1-meter of drone.  


From start of flight (at 2.9s) the log shows drone has compass error.  

An indication that there was magnetic interference at takeoff point or compass needed calibrating.  There is possibility that compass itself has hardware problem.

v01d Posted at 4-23 01:58
If the drone already took off (like say couple of secs after), does it matter that car drove upto me at the back , close?

The parking lot is asphalt, but I'm not sure on the spot I took off from.  It could have been a cement plate, i need to check.

Won't the drone complain about compass if there is magnetic interference? I think when there is, it usually complains about it before take off - am I wrong?

It should.  But it may not always.  


(Further testing needs to be done.)  Whether drone detects marginal amount of magnetic interference as being a problem, may come down to whether drone was already powered up when it is placed near magnetic interference.

v01d Posted at 4-23 01:54
I have filed the support case, and already dropped off the drone for check / repair.  I 've referenced this thread too for my description of the issue, like the log link. Although, DJI guys probably will extract log themselves...

I accidentally walked into the "personnel only" room, and , saw tables and bunch of technicians testing / troubleshooting drones.  Also, a netted area for testing. Wow, looked like a spy/military facility , lool (for someone with big imagination .. ). Unfortunately they quickly booted me out, to the depo / receiving dept.

Yeah they will look after you, they won’t let craft out unless it’s fit for full use, if repairs are too much they will always replace with new or refurbish which by all accounts are exceptionally good .
Pity you didn’t get a couple of shots of repair centre ;+) ...

Still under investigation.

Asked me for full flight logs, and video.   Unfortunately no video of that specific flight,  I planned to start recording only once in the air ... bummer.

Said, 3 - 5 working days ... I hope they hurry up before my trip to Africa.

'Lo dudes,

Got my drone back. Well, actually not my old one, they have replaced it with a different unit.   I cannot say, if it's brand new - it had stickers on gimball, back and front, but , the USB port looked used, and ,  I couldn't say.  When asked the guy before taking it , he said, "DJI policy is that we don't replace with refurbished unit. We gave you one new from production line".
So I go by that.

Anyway, reason for failure : I did not get any , initially. I mean, we knew it was compass, but why / what caused it, I will never know.   Initially, they gave me nothing in terms of , what was wrong with my original one.
Before leaving with my replacement, I asked that I want to speak to a technician regarding my original unit, and why was it replaced / not fixed.

So a guy came out to speak to me. He said, component failed on motherboard, and we don't replace it without the board. So , we replaced the drone.   Now I don't know if component was the compass, but that's all I got. And the guy wasn't super at English, and even though I tried to ask if it was the compass, I didn't get more.  All I know the drone did fly after that failure, and returned, but , I could have been faulty anyway.. (one thing, it was kinda drifting even when supposed to be still, on a flight... anyway).

So.  I have no idea why it failed as it was, but , I got replacement relatively quick, thanks to DJI service (and I bet my DJI care refresh yearly charge, that I didn't pay anything).

The bad thing: no clue why compass (and anything else .. ) may have failed. Thus, always need to be careful what's around me, when taking off... Not just for drone, for other people mostly reason.

PS : Question: anyone ever used that Emergency Motors Off with the remote controller ??  I wonder if I need to practice that combo to be very quick when need arises ......