For context, in April I bought my first M3P and after 9 days it died mid flight, fell from the sky and smashed.  It was 30m up and flying full throttle forward in S Mode.  The S Mode and full throttle being relevant to the next part.  DJI examined this drone and replaced the whole unit, drone, RC and battery.

Fast forward to the replacement's first flights.  Having needed to regain flying confidence I went to an open area and practiced normal moves.  I then decided to try full throttle forward in S Mode, I set the height to 6.5m and off i went.  To my horror, after 2-3 seconds the drone shot vertical to 78m at an extreme speed (4 rotors screeming) before lowering itself to an uncontrolled landing.

I have now recreated this scenario and it does this everytime I fly forward in S Mode.  You can see it here on Youtube.  https://youtu.be/-7gi3LfIUuM

I will be contating DJI in the morning but after forking out over £1k and having to send back a drone that fell from the sky after 9 days for the brand new replacement to have this issue at 2 days old.  I'm not overly impressed with the experience so far.  I was looking forward to the fun of flying, the images I was going to capture and my only fear was my flying abilities.  Now I have fears of trusting the kit.

Has anyone any experience of this rocket to the sky scenario?  Anything I should say to DJI?

Thanks.  

DO NOT for the moment sync your logs with DJI.

If you use the RC231 and a phone go to
https://www.phantomhelp.com/LogViewer/Upload/
read the instructions there, retrieve the .txt flightlog i.e. copy all those flight logs to your computer, upload relevant flight logs to that website and post the resulting links/URLs here.

In the folder where you should have found the flightlogs there is a folder whose name starts ''MCDATF''. Open that folder and it will contains .DAT flight logs. Copy ALL those  flight logs to your computer.

If you use the DJI RC then have a look at https://forum.dji.com/forum.php?mod=viewthread&tid=287726
retrieve the .txt and .DAT flight logs and blah blah blah as above.

Once we can see the flightlogs we can tell you which DAT flight logs may be interesting.

Sean-bumble-bee Posted at 5-14 12:36
DO NOT for the moment sync your logs with DJI.
P wanted to get that message out there ASAP, for to follow

Auto sync was on.  Too late I guess.

Sean-bumble-bee Posted at 5-14 12:36
DO NOT for the moment sync your logs with DJI.
P wanted to get that message out there ASAP, for to follow

I can however recreate it again and not sync the log.
Not that I have any knowledge with reading logs.  

I have added to the previous post, it might be worth reading before you fly another flight
SWITCH syncing off before you fly any more flights, sync may well delete the DAT's

Sean-bumble-bee Posted at 5-14 12:49
I have added to the previous post, it might be worth reading before you fly another flight
SWITCH syncing off before you fly any more flights, sync may well delete the DAT's

ok, Thanks for this.  Sync off and will recreate in the morning and grab the data.
I really would like to see what can be obtained from it.
I shall post tomorrow.

Paul_in_NI Posted at 5-14 12:55
ok, Thanks for this.  Sync off and will recreate in the morning and grab the data.
I really would like to see what can be obtained from it.
I shall post tomorrow.

You should still have txt flight logs even if you don't have the DATs and it will get the log gurus started.

Sean-bumble-bee Posted at 5-14 12:36
DO NOT for the moment sync your logs with DJI.

If you use the RC231 and a phone go to

I hope I have managed to do this right with the txt file.

Does this work?  https://www.phantomhelp.com/logviewer/20Q97OPKGAUISLDZPELK/     (sorry link won't work, not alowed)

First thing I see is it reporting going to -67 feet before shooting to 250 feet.   It was fixed at 21 feet (6.5m).   Strange.   

Paul_in_NI Posted at 5-14 13:50
I hope I have managed to do this right with the txt file.

Does this work?  https://www.phantomhelp.com/logviewer/20Q97OPKGAUISLDZPELK/     (sorry link won't work, not alowed)

Yep that works, now we just have to wait, for one of the gurus.
You might like to keep an eye on
https://mavicpilots.com/threads/ ... 37610/#post-1551735

which is an similar, Polish, Mavic Mini thread over on Mavic pilots.

Sean-bumble-bee Posted at 5-14 15:25
Yep that works, now we just have to wait, for one of the gurus.
You might like to keep an eye on https://mavicpilots.com/threads/ ... 37610/#post-1551735 which is an similar thread over on Mavic pilots.

Interesting.

Thanks for your help.

Paul_in_NI Posted at 5-14 15:33
Interesting.

Thanks for your help.

And possibly this USA mini 2
https://forum.dji.com/forum.php? ... D915%26typeid%3D915
What controller do you use?

Sean-bumble-bee Posted at 5-14 12:49
I have added to the previous post, it might be worth reading before you fly another flight
SWITCH syncing off before you fly any more flights, sync may well delete the DAT's

Sean, can I use the dat files the same way I used the txt file? Or, how do I (or someone smarter) read them?

You need csvview or DatCon to read the DAT
https://datfile.net/CsvView/downloads.html
CsvView will also process the csv from phantomhelp and it generates graphs from those, it can process the Mini 3 Dat directly.


Oh forgot to say phantomhelp can not process DATS

Hi there. Thank you for reaching out and we're deeply sorry to know the incident happened to your unit. I'm afraid that you may consider sending the unit in for a proper diagnosis. You can contact our support team to start up a ticket at https://www.dji.com/support . Also, the warranty can be applied depending on the outcome of the damage assessment including the warranty period of your unit. Thank you for your understanding and support.

Paul_in_NI Posted at 5-14 12:44
Auto sync was on.  Too late I guess.

If you ever need to get an original log file back,  create a free account at airdata.com and connect your DJI account to it,   Airdata can then sync logs from DJI and they give you a link to download them.

Hi

Had a look at your flightlog and video.
There must be another log, as the controlled landing is not in this part.

Bad experience to see you drone fly UP uncontrolled and goes down uncontrolled.
Log shows out of the normal data, starts at 2m43s in flight
Baro height into negative numbers, from 6.6 meter height to minus 20.5!
Vertical speed also into negative numbers!  so your drone thinks it is actual descending. so needs to go UP to correct this.
Climbing to max 78 meter. (as the values goes weird mayby it did not go that high, values it the log can be wrong)
About 6 seconds of climb = 6 * max vertical speed = approx 35 to 40 meter actual height.During this climb the vertical speed not that high in the plus values, also not correct imo.

This all indicates a barometric height sensor fail, or baro signal processing fail in the IMU, or ofcourse just a IMU fail.

"screeming motors"  yes...warning in the log  "Battery overcurrent. Maintain smooth flight and check if aircraft is overloaded"

Only thing you can do is a IMU calibration and test flight again.
Or wait for a DJI reaction, probably a warranty case.

TIP I always fly with a screen recording active, after each day of flying download the log and dats to your computer.


cheers
JJB   [ Charts by FRAP ; the 'best' software for flightlog analysis ]

DAFlys Posted at 5-14 22:43
If you ever need to get an original log file back,  create a free account at airdata.com and connect your DJI account to it,   Airdata can then sync logs from DJI and they give you a link to download them.

Good TIP

Or log into your DJI account on another mobile device.
Sync and video play back the flight, this will transfer to flightlog.txt back from DJI server to your device

cheers
JJB

JJB* Posted at 5-14 23:48
Hi

Had a look at your flightlog and video.

JJB,

Thanks I really appreciate this.  

Yes, I did notice somehitng missing about the last moment of landing being missing.  However, not looking through experienced eyes.

I have contacted DJI and it is going back for assessment for replacement.

I am going to take it out just now to recreate this and gater the DAT file this time.  Would that provide deeper analysis here?    I will IMU calibrate and screen record.  

This is really denting my flying confidence.  I thought getting a drone and diving deep into the learning curve whould have started with pilot errors and was keen to become good.  However, two brand new M3P doing their own thing make it feel more risky than just progressing my performance.

Something good to take from it will be learning about flight data I guess.!

Paul_in_NI Posted at 5-15 01:04
JJB,

Thanks I really appreciate this.  

Hi Paul,

I fly DJI drones for many years now, only once i had a bad experience with a MINI1.
Bad luck to have 2 MINI3 with issues.

Most values in DAT files are hard to understand, but some values in easy to understand.
Motor Revs can be usefull to see sometimes, in your flight going UP with a battery error - max revs that time, wich is logic as it tries with all its power to climb as the height is showing negative numbers.

Just screen record all flights and after day flying analyse the flightlogs with the screen recording.
FRAP can be usefull to do this.

https://forum.dji.com/forum.php? ... D572%26typeid%3D572

cheers
JJB

JJB* Posted at 5-15 01:54
Hi Paul,

I fly DJI drones for many years now, only once i had a bad experience with a MINI1.

JJB,

Just been out to do one more flight and the screen record shows amusing height data.

Screen record is here  https://youtu.be/q8rgbputsL0

Flight log is here https://www.phantomhelp.com/logviewer/27YZ634A5LPE5SO1QIDS/

Drone just thinks it is at the wrong height!

Paul_in_NI Posted at 5-15 02:14
JJB,

Just been out to do one more flight and the screen record shows amusing height data.

Did you get a DAT?.
if so can you upload it to a file hosting site and make the page public / shareable please?

Paul_in_NI Posted at 5-15 02:14
JJB,

Just been out to do one more flight and the screen record shows amusing height data.

Hi Paul,

Did you calibrate the IMU before this flight ?

For sure a faulty drone!  and a warranty claim.

cheers
JJB

Sean-bumble-bee Posted at 5-15 03:55
Did you get a DAT?.
if so can you upload it to a file hosting site and make the page public / shareable please?

Does this work?

https://www.dropbox.com/s/oobx77fkodcpa7u/2023-05-15_10-31-34_FLY025.DAT?dl=0

JJB* Posted at 5-15 04:21
Hi Paul,

Did you calibrate the IMU before this flight ?

JJB,

Yes, IMU and compass immediately before.

It is crazy behaviour.  That last time it decended very slowly then decided it needed to go higher.  I had to bring it down.  Glad it let me!

Paul

Paul_in_NI Posted at 5-15 04:23
Does this work?

https://www.dropbox.com/s/oobx77fkodcpa7u/2023-05-15_10-31-34_FLY025.DAT?dl=0

i am not a specialist in DAT logs, but...this one is easy

many many IMU errors, after powering UP and before starting motors

No FlyApp error ?  really strange.....

{IRQ52}CRITICAL:dgs imu dma unfinsh! 17|||{IRQ52}CRITICAL:dgs imu dma unfinsh! 18|||{IRQ52}CRITICAL:dgs imu dma unfinsh! 19|||{IRQ52}CRITICAL:dgs imu dma unfinsh! 20||
In flight at the time where your drone goes in error...
Height_ctrl_failed!   yes    we knew this already.....

Motor revs in sport mode fully forward = approx 9000 rpm, during uncontrolled climb approx max 13000 rpm.  values in my chart x 10

cheers
JJB

JJB* Posted at 5-15 05:04
i am not a specialist in DAT logs, but...this one is easy

many many IMU errors, after powering UP and before starting motors

JJB,

You are a star!

Nice summary prepared for DJI to go in the package.  Hopefully a quick turnaround and I can actually try some flying!

Paul

JJB* Posted at 5-15 05:04
i am not a specialist in DAT logs, but...this one is easy

many many IMU errors, after powering UP and before starting motors

You might like to have a look at post #23 in https://mavicpilots.com/threads/ ... page-2#post-1553312

Sean-bumble-bee Posted at 5-19 06:16
You might like to have a look at post #23 in https://mavicpilots.com/threads/mavic-mini-1-stuck-at-full-throttle.137610/page-2#post-1553312

yes, but not only the acc meter goes wonky  same for barometric values.
So not the acc but the imu handles multiple signals in error.

cheers
JJB

Before you did the 1st flight, did you do any calibrations?

nice, thanks

Bashy Posted at 5-19 19:45
Before you did the 1st flight, did you do any calibrations?

Yes, IMU and compass.

Paul_in_NI Posted at 5-21 01:34
Yes, IMU and compass.

That could be your problem then, you could have calibrated the compass next to something that caused interference, then when you took off and flew out of the interference area thats when the issues start...

JJB* Posted at 5-19 07:13
yes, but not only the acc meter goes wonky  same for barometric values.
So not the acc but the imu handles multiple signals in error.

JJB* have you seen this
https://forum.dji.com/forum.php?mod=viewthread&tid=290600
Title =  "Qu for DJI, unwanted extreme climbs & "Anytime" CSC ? "
In the Mini 3 pro forum.

As way of an update.

DJI has found a defect and is replacing a 'circuit board module'.  
I have raised an issue about receiving a repair instead of a replacement.  My new M3P was to be replaced after 9 days under the 15 day replacement policy.  They sent me a replacement and it was defective.  Now they are reparing this defective replacement.  
I have asked them to provide a suitable replacement to the initial defective item instead of ending up with a repaired drone as a new for new replacement!.

In my first month of DJI ownership, I have owned two confirmed defective drones.  Most of this month these drones have been with DJI.  I am still to have flight time.

This was a hard purchase to get wife approval.  I must say, the defective drones have made my purchase look like a really bad idea in her eyes.  Starting to think so myself too.

I think you have had bad luck, whilst the climb is of a concern DJI drones are fairly reliable. I have probably just tempted fate by saying that, persevere until you see how the third one goes. Was the second one new, did you have to activate it?
I would suspect they will send out a new or refurbished drone rather than repair you no2 .... unless they have no stock of new/refurbished drones.

Sean-bumble-bee Posted at 5-22 10:07
I think you have had bad luck, whilst the climb is of a concern DJI drones are fairly reliable. I have probably just tempted fate by saying that, persevere until you see how the third one goes. Was the second one new, did you have to activate it?
I would suspect they will send out a new or refurbished drone rather than repair you no2 .... unless they have no stock of new/refurbished drones.

Yes, I had to activate the replacement.  It came as a complete sealed package with RC.  Unfortunately it didn’t know how to determine what height it was flying at!
The case for this one is showing as a repair with replacement board.  I will hopefully get it for the weekend and thoroughly test it.   DAT files and screen recordings will be kept.   Amazing what you learn when things break!

Further update.

So, despite DJI sending me an itemised repair email stating a defect and is replacing a 'circuit board module'.  Quoting price for parts and labour cost then covered by warranty.  Today I got a call to say they were unable to replicate the issue at all but have dispatched a replacement drone to me.

I have the UPS tracking saying this arrives tomorrow.  Intensive testing to follow!

Replacement arrived.
Tested and behaving normally.
Finally, after two faulty drones time to start flying.
Thanks everyone for your help on this topic.  (JJB*  & Sean-bumble-bee)

Whey hey.
So, showing my age we want you to be doing

and not

Paul_in_NI Posted at 5-25 12:22
Replacement arrived.
Tested and behaving normally.
Finally, after two faulty drones time to start flying.

Two new drones with the same error? That is really strange but am glad that you are satisfied now and the third drone doensn't have any issues. Safe flying!