Mini 3 disconnect and unresponsive

[Cymru]

OK its not a crash or flyaway as such but its the second time its happened now.

Flying my Mini 3 Pro in a rural setting (no interference). Drone clearly visible some 240m away and 90m high, just hovering whilst thinking how to compose a shot.
Signal indicator showing full strength, clear path line of sight etc.

For no reason i can see it suddenly went to "Aircraft disconnected" with no warnings or prompts on the screen. Drone also unresponsive to the sticks, just hovering.
Closing/reopening the fly app did nothing, neither did restarting the RC-N1 itself.

After a while the drone eventually RTH'd and landed. Given the Mini 3 lacks precision landing i was lucky - it landed about 2m from the takeoff point and about 1m away from a river...This is why i miss precision landing!

Unfortunately it seems unlike Go4, Fly removes the .DAT and TXT files after upload so ive got no way of extracting proper data from the phone itself so the only info i can provide is AirData.









At no point was i able to reconnect with the drone, even stood next to it.
Power on/off cycling the drone itself immediately reconnected and the flight repeated with no issues.

The only thing i did notice was a longer than normal time writing files to the SD card after taking an image. This card was as always formatted immediately before the flight and has never given me any issues before or since. It also scans OK in a computer. All images and videos taken are fine and uncorrupted so this COULD be unrelated.
Im wondering if its a CPU load issue causing slow writes and then going completely unresponsive. Its clearly not an actual signal strength issue.

It happened to me once before some 30 or so flights ago, again no more than 150m away and in clear sight.

Anyone else seem similar or hazard a guess as to what went wrong? The failsafe worked in that it returned home but obviously thats far from ideal and without precision landing could result in loss of a drone if the area is somewhat tight.

 

[Yorkshire_Pud]

With regards to the logs.
The DAT would be useless as it is encrypted and you can download the original .txt from Airdata, on the general tab click on "original" from the list low down on the page.
For that matter I'd be fairly certain you can prevent the upload of logs to DJI in the first place, at worst you can almost certainly remove the phone from the permitted devices on your WIFI transceiver.
On my phone I have to authorise syncing ..... and I do not plus I switch the phone WIFI etc. OFF.

With regards to the Airdata page shown in your post, I think you would do better to make the page public and post a link to it or download the log and then upload it to Phantomhelp and post the resulting URL here.

 

[Macinfo]

I do not recall the logs being deleted from the device after any sync, though I could be wrong and have something disabled that prevents that to begin with.

in regards to the problem, it does seem like its a RC issue, though it seems odd that it would not recover if you restarted the RC while your Mini is stuck hovering. You'd think after a restart it would reconnect to the Mini, you really don't need Fly to control the Mini, the RC should control it whether Fly is running or not as I recall.

Since you say this has happened twice, I'd ponder opening an incident with DJI to perhaps have them fix or replace the RC and perhaps the Mini..

 

[Cymru]

I suspect a drone more than an RC issue as control only came back (immediately) when the drone was power cycled as opposed to the RC.
I generally keep auto sync on for logs as it links into Airdata but wasn't aware that unlike Go4 it deletes them after upload so thats my mistake.

I'll grab the full .txt off Airdata and change some permissions as suggested.

 

[Yorkshire_Pud]

You can always upload logs to Airdata manually.
I move all logs off the phone to external storage, any logs I temporarily upload to airdata are uploaded from that storage.

 

[Cymru]

I could do (and used to do that) but when things are working normally its easier to just have them go without needing manual action.
Main issue is i wasnt aware of the change in behaviour from Go4 to Fly in deleting them once sent.

 

[globetrotterdrone]

I had a complete disconnect about a month ago and was not able to regain control at any time with the Mini 3 Pro and the DJI RC. Although being quite certain that there were a lot of signal interference in the urban area, I have never experienced anything like this with the Mavic 2 Pro and the Smart Controller.

Spoiler: Incident

First the video stuttered, soon the telemetry and controls were gone and I was never able to rejoin even after a complete restart of the RC (Drone view remained grey, when closing the app The "Fly" button was not showing up).

Luckily the drone returned home as set after a few minutes but on descend and missing precision landing and to some degree to my fault, the landing spot had was a tight fit. Of course the surrounding beams were an obstacle and the sensors recognised them partly, leading to a halt in about 2,5 m height. Having a ladder nearby, I tried to grab it, but in these few seconds to get it, the drone wiggled around and descended just to hit an edge of the construction in about 1 m height after on and fell down.

On inspection only the props seem to have suffered and 2 small bruises on the body. The gimbal needed a recalibration, but that was about it

Now after all the time, I yesterday compared some before/after photos and discovered that part of the optical system seems to have suffered to, as a small part of the image now is blurry, seems out of focus.

So long story short, I've made a claim with DJI Care Refresh Express to cover it but coming back to your incident, I truly have to say, this leaves a very bad feeling for future flights. I got the impression that upon signal loss, DJI Fly also got locked up in a strange manner.

I should have made the FCC hack earlier with the DJI RC, because after I did that, I never encountered any loss again (yet the camera/sensor was already misaligned).