I have DJI's QuickCare on my DJI Drone, and recently sent my Mini 3 Pro for service as one armature felt loose and received another (new or refurbished?) back.
I had no qualms with this replacement, but I notice that the distance and connection with my RC seems to not be as solid. Now to be fair my flights haven't tasked the range as much. However, two days ago I am on Brasstown Bald, high point, One flight with the extended batteries NO problem.

Second, Eveything seemed ok, seemed as if I was facing the drone's direction, clear sky. It was higher than my point -- but when I dipped I went from full strength to red. So I brought the drone back and higher. RC signal stablilized. Tried to spin around and bring the drone in for a final pass and landing and it just went down.

Loss signal no RC connection -- mind you it was closer than the first times it was giving me red warning. My phone flashed one final signal and I knew.. it was down, I saw a flash of blue sky.

Trekked down the mountainside and retrieved it. It was sitting in a low branch, like it had coasted down and not flown into a tree. No damage and not even propellor damage. It was however hanging camera side up caught on a thin branch. Could not connect to it with my remote to produce a sound until I was like 100-50ft away (39-28m)

Took it home pulled all the images. Tried to piece together the flight data. No errors in the logs with regards to connection. It just .. goes.. down.

I reflashed the firmware on the RC and unit. Took it for a test flight yesterday, again seemed ok. Sometimes (and this happened with my previous drone and this one) I will get a slight image transmissions miss where 2-4 frames are dropped and then it picks up. Especially metro I guess RF intereference? However, I am highly concerned with this. I keep trying to find information why it went down in the first place. The "where's my drone" footage on the phone does not even duplicate exactly what I saw (that flash of blue at the end). I do not think I hit a tree, or anything. Last data in the log shows it was going down around .1 mph then 0.0. Super odd.

COuld there be something wrong with this replacement? I do not want to pay (and go without a drone) and then be charged for shipping and some "cause" that is a attributed to a crash that may have been there prior? I don't know. Super nervous about flying this drone anywhere right now though. I have refreshed the firmware on both RC and Drone. Not sure what else and it does seem to respond well. Take off I do a quick maneuver check, hover 2m, f 2m, back 2m, strafe l/r 2m, etc and it seems fine and remain in hover mode with good satellite coverage. Just wondering if I am missing something or if I should do something else to ensure it doesn't fall out of the sky like that again

Sounds like a fun hike to find the drone!  Good for you for finding it at least!  The forum won't be able to help much unless you post the log though.  https://www.phantomhelp.com/logviewer/upload/

If you are really concerned about the drone and think something is wrong, I would send it in for service.  

Are you checking the spectrum analyzer in DJI Fly to see if there is interference?  Have you considered using some manual settings to test if frequency selections help?

https://www.phantomhelp.com/logviewer/upload/

You would have to post the entire log to phantom help, so we can look for red errors.

I had a crash where an impact was involved, but I could not connect with it, but it was still on and recording video. The impact was bad enough to damage the GPS module.

I don't know what QuickCare is, and how many crashes it allows. I would do more extensive testing, at 5km ranges :-)

TonyPHX Posted at 3-21 06:22
Sounds like a fun hike to find the drone!  Good for you for finding it at least!  The forum won't be able to help much unless you post the log though.  https://www.phantomhelp.com/logviewer/upload/

If you are really concerned about the drone and think something is wrong, I would send it in for service.  

To be honest, I have not used the spectrum analyzer.

Here is the link to the Phantom log viewer: https://www.phantomhelp.com/logviewer/25PW5U103CN44JLRP9AI

(should I create another thread in the help topics too?)

-- Also not QuickRepair or whatever I guess DJI calls it Refresh Care -- for faster service but of course there are still costs involved.

PS -- For the record -- it was .. an INTERESTING hike into a mass of NOTHING and areas clearly not traversed by humans for a very long time! I was just happy I was able to climb down and back up over to get it. If it had pitched down further away I wouldn't be sure.

** I guess what gets me is if the drone loses RC connection it IS supposed to RTH correct?

Hi there, we are sorry to know about the accident. Out of flight safety and warranty maintenance considerations, we recommend that you start a case through the link below and send the drone in for a further diagnosis. If there is a doubt about the accident, data analysis can also be applied as long as the drone is within the warranty period. http://www.dji.com/support

Unless I am up a gum tree you had the throttle fully closed 3 times in the last five recorded seconds and it was closed when the log ended.

The Failsafe includes "f the aircraft is farther than 50 m from the Home Point, the aircraft adjust its orientation and flies
backwards for 50 m on its original flight route before entering Straight Line RTH. "

I recollect JJB checked whether or not the retrace is 2D or 3D but we will have to wait for him to comment on that.

How tall was the tree, how far below the launch point was the top of the tree, how far from the drone's last recorded position of the drone was the tree and in what direction was the tree from the drone's last recorded position?

Sean-bumble-bee Posted at 3-21 08:43
Unless I am up a gum tree you had the throttle fully closed 3 times in the last five recorded seconds and it was closed when the log ended.

The Failsafe includes "f the aircraft is farther than 50 m from the Home Point, the aircraft adjust its orientation and flies

Would this be regardless of safety height? Or when you mean straight line RTH it goes up from the point to the safety height, line to home spot, line down?

I was stopping as I was getting image errors and I was literally walking closer to the drone. I was confused why I was having errors.

I was just reading that I should adjust compass and IMU  when changing elevation and distance from last flight -- could that at all be a cause? Thinking about it makes sense, this was drastic change from normal flight areas for me (like 2k feet) and I did not do that. Now I took a previous 40m flight (more leisurely and higher around the area) and did not notice any problems. This was a battery switch and re-take off that didn't last very long.

Safety height?

Or when you mean straight line RTH it goes up from the point to the safety height, line to home spot, line down?
Not being awkward but I quoted the manual, it's explained in the manual.

I was just reading that I should adjust compass and IMU  when changing elevation and distance from last flight -- could that at all be a cause?
Doubtful, I don't have a mini 3 pro but there are folks about who have never done ether (calibrated the IMU and or compass) and they fly in varied locations, I think I have calibrated an IMU 2 or 3 times in 3500+ flights. The compass? Only when asked to do so and I suspect I could have simply moved a bit or switched the drone off and on again and not needed to do a compass calibration, the most common time is when I walk past a stell post in the house whilst carrying a switched on drone outside.

How tall was the tree, how far below the launch point was the top of the tree, how far from the drone's last recorded position of the drone was the tree and in what direction was the tree from the drone's last recorded position?

Sean-bumble-bee Posted at 3-21 09:38
Safety height?

Or when you mean straight line RTH it goes up from the point to the safety height, line to home spot, line down?

Drone should have been approximately 20-40ft above the treeline prior to it descending.

It was showing full strength at the time on the app and went from full signal to a flash of the sky to disconnected from RC in a flash.

It was total RC disconnect until I got around 100ft from the aircraft and then it paired where I could create the noise/flashes. Seems strange to me that within 400ft I would lose signal as it was elevated above my position and I was facing the aircraft.

All i can make out is that you had 100% stick down at the time the flight log ended

LT56-DV Posted at 3-21 10:16
Drone should have been approximately 20-40ft above the treeline prior to it descending.

It was showing full strength at the time on the app and went from full signal to a flash of the sky to disconnected from RC in a flash.

If the retrace, whether it be 2D or 3D has no concern about your safety margin, it merely reverses the inbound flight path.

Since you have not answered either of my "How tall was the tree, how far below the launch point was the top of the tree, how far from the drone's last recorded position of the drone was the tree and in what direction was the tree from the drone's last recorded position?" questions I will ask directly.

Since you were commanding full descent at the time of disconnection is it possible that you lowered the drone into the tree?

Hi,

Had a look at your flightlog too, see my charts of your data.

In the map chart the orange part is where the up and down link RC<>drone is really bad.
See the other chart as well for this.

For the best signal reception RC<>Drone, the radio signal needs also 'free' line of sight. Perhaps this was not the really the case flying lower than your starting point.
Depends also ofcourse of your postion omn the view point. (wich i do not know ofcourse)

What i do not understand ;Last position of drone ground level approx 40 meters lower that starting position.
Baro height last record 18.8 meter, thus fly height approx 60 meter above surface below.
uh ??  really high trees...nah.

Fail safe action was RTH, so if it lost conection it should fly home   not 'landed' at last postion.
As the distance out = 126 meter, in a failsafe RTH it should climb to your RTH height setting of 130 meter (bit high....cost too much battery life for nothing...)

Note: height line in chart is too high, as i made a plus correction to all heights, if not than line would not be seen ( below surface values not showm in GE)

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

Sean-bumble-bee Posted at 3-21 08:43
Unless I am up a gum tree you had the throttle fully closed 3 times in the last five recorded seconds and it was closed when the log ended.

The Failsafe includes "f the aircraft is farther than 50 m from the Home Point, the aircraft adjust its orientation and flies

checked   retrace is 3D

Cheers JJB

JJB* Posted at 3-22 00:58
Hi,

Had a look at your flightlog too, see my charts of your data.

This is great info. The obsevation area is two floors, where the upper area is about 2 standard floors higher than the ground. I wanted to bring the drone in to the lower area first as people were flowing in from that side.

I was pushing down at the time as I had room... but at the loss of connection it must have kept going down just enough to clip a branch then. I do recall hearing the whirring of the drone in the air after losing connection (high altitude could hear it clearly) I did have LOS as I was perched higher for the flights that day but maybe at the angle I was, the observation deck, elevator, area cut signal.

Thanks for the answers everyone. Fortunately I think the drone is A-OK.. Taken it up again and seems to fly and hover to different spots perfectly. Glad it was me, not a failure or a pteradactyl or something.

Ahhh the Google Earth plots have just shown up for me, not sure why they didn't earlier.

Maybe it overheated. It would explain connection loss and landing on the spot as that is exactly what happens if this model overheats.

Tuxtard Posted at 3-22 12:30
Maybe it overheated. It would explain connection loss and landing on the spot as that is exactly what happens if this model overheats.

Maybe it overheated.
It didn't overheat.
The recorded data shows that the temperature only rose from 54°F to 63°F during the flight.

While flying seems ok -- there are still some quirks too. This happened while flying on Brasstown:



This happens when I change filming modes, and now will not do 360 or Wide angle panorama it will take 1-2 pictures my screen will go gray and it will just stop. Maybe in 60-70 seconds it will take another, but far from the responsive and fast 360 im used to seeing. Other times the image will just freeze for 3-4 seconds (which feels like an eternity) with full bars.

Starting to think I got a lemon

LT56-DV Posted at 3-28 05:36
While flying seems ok -- there are still some quirks too. This happened while flying on Brasstown:

[view_image]

I would start by trying a new SD card in the drone to see if it is storage related somehow.  If you have reflashed firmware, and reinstalled the app on the mobile device and still no improvement, then yes, your symptoms may be lemon like.