Phantom 3 Pro ends mission abruptly, goes into ATTI then GPS, a couple of times…screen locked up, no screen telemetry.

[rpm3]

Pardon me if I’ve missed some posting protocols….kindly point me in the right direction if so!

OK...(long post), but I'm looking for some confidence building feedback!!!
It was recommended to me to ask for the analysis of @sar104 and/or @Meta4.


Phantom 3 Pro,
Litchi App Ver 2.6.2
Mission ended abruptly...
That's it...no warning....trans signal was 100%

Distance- ~2000', in line of site, no obstacles (over a river)
Alt- ~40' over river
150' from metal bridge
19 satellites
I have flown here numerous times, no issues....even have flown over, and behind the bridge...rock solid...
soooooooo…...

I lost all feed, video, telemetry all of it.
I had a fresh battery, I could see it, so fortunately I had some time to sort it out....after I stopped my knees from knockin
I had no idea about orientation, it was out 2000'....so fortunately I figured it out and hustled back.
Yesterday I had the same (similar) issue...same mission, but it was even closer to me....I brushed it off as me hitting the switch that changes flight modes, but didn't really think I did, and now I KNOW I didn't inadvertently bump a switch.
Links to both logs are below. I also have 2 links for screenshots from airdata log from where the same issue came up...I took a screen shot...., you'll see the bird went into ATTI mode, then GPS ...back and forth a few times.... I see I went from 19 satellites to "0" satellites in .2 (2 tenths) of a second on the 10/23/18 mission.

ok...so now I'm a bit nervous, about flying...what say you, Phantom 3 Pro experts?

thanks in advance

Ralph Matile

https://www.dropbox.com/sh/kqecg018ifgbunz/AAAQKNcw5vky69sXt-UfHSAqa?dl=0

 

[Fly Dawg]

Links to both logs are below.

You do not have your shared folders configured correctly in dropbox....not accessible. Start by FULLY sharing your Airdata Flight here such that the .csv can be downloaded. Then correct your dropbox account and we can go from there.

 

[rpm3]

Thanks Fly Dawg... there are the DAT files, right off of the Phantom..., as well as CSV files from Airdata

https://www.dropbox.com/sh/kqecg018ifgbunz/AAAQKNcw5vky69sXt-UfHSAqa?dl=0

 

[sar104]

You are correct - the mission was ended because the satellite count briefly dropped to zero at 116 s and again at 122 s. I don't see any obvious cause - it doesn't look like a comms problem with the GPS module. You were 220 m from the bridge.

 

[rpm3]

OK then, how would you go about troubleshooting this?
Thanks sar104 for the confirmation....
So, I've flown probably this mission 20 times....some before AND after these 2 GPS failures, and not had this issue.

It happened so abruptly, it seems to be a hardware issue, not software....it also seems to be an on board drone issue, not a controller issue, like a loose wire for the antenna GPS connection?...I am way outa my knowledge base, so I sure could use some feedback...

I don't mind opening the bird up and snooping around, but would like to hear others feedback before I do....also....it seems all the "stuff" inside is so integrated....if its not a loose connection....probably have to remove/replace a main board....anyway....this has been a great drone for me.....getting ready to buy the MP2, but I DO NOT want to bench this yet....I'd like to keep it going a LOT longer!

 

[sar104]

OK then, how would you go about troubleshooting this?
Thanks sar104 for the confirmation....
So, I've flown probably this mission 20 times....some before AND after these 2 GPS failures, and not had this issue.

It happened so abruptly, it seems to be a hardware issue, not software....it also seems to be an on board drone issue, not a controller issue, like a loose wire for the antenna GPS connection?...I am way outa my knowledge base, so I sure could use some feedback...

I don't mind opening the bird up and snooping around, but would like to hear others feedback before I do....also....it seems all the "stuff" inside is so integrated....if its not a loose connection....probably have to remove/replace a main board....anyway....this has been a great drone for me.....getting ready to buy the MP2, but I DO NOT want to bench this yet....I'd like to keep it going a LOT longer!

I'm not sure what to suggest. GPS hardware issues generally seem to result in errors in the event stream, but there were none in this case. A loose GPS antenna connection might cause this kind of effect.

 

[Fly Dawg]

Oddly enough, the other flight does not show sat count drops. However, the mission did drop and the AC was in and out of ATTI. Haven't looked at the .dat files. These are just the 2 .csv's that you linked. Not sure what to make of that. One appears to be a GPS issue. Maybe the other is related or possibly 2 different issues causing similar responses?

This is the flight with the GPS dropouts. The other flight is right underneath.

 

[rpm3]

Thanks,
I noticed that too Flydawg….in the mission showing no dropped satellites, what I was thinking is that it lost all satellites long enough to lose connection, but not long enough to record the event.....but maybe it doesn't work like that....

I gotta believe that the mission ending, and loss of control is related to the same problem in both missions, however the data doesn't necessarily reflect, that does it!?!!??

So my dilemma is how to go about trouble shooting, and correcting...with what I've got....a bit of inconsistent info.

IF I fly this bird, I will not fly it at any great distance, and that certainly limits the usability, and enjoyment!

It has not had any hard landings, crashes, its been treated with care.....but just based on what I know, I think the issue is AT the drone, and not at the controller....would you guys agree? the reason I am saying this, is I did add a range extender in the controller months ago..many flights since then....but that wouldn't seem to be related to the drone indicating its losing satellites....would it?....doesn't that satellite data get recorded, and stay on the drone....independent of the controller?

 

[rpm3]

So yes...there can be 2 different mission ending events, one involving the controller, going into ATTI mode, and no lost satellites, and another involving the drone, with a GPS antenna issue....at ALL times the controller shows 100% signal.
The antenna I installed many missions ago...
ITELITE - DJI Range Booster ITE-DBS02.2X

I am trying to shrink the trouble shooting universe down to a reasonable, and manageable size!

 

[Fly Dawg]

I think the issue is AT the drone, and not at the controller....would you guys agree?

I would agree with that. Also, looking through the .dat files, both FLY406 and FLY414 are dated OCT 23rd. One of the .csv's you shared is dated OCT 22nd, ( which is the one I graphed above). That's ok, but it really got confusing when trying to differentiate the two at first while looking at the .dat's.

 

[Fly Dawg]

I am trying to shrink the trouble shooting universe down to a reasonable, and manageable size!

The above being said, these errors are from FLY406......No GPS dropouts, but errors none the less.

Below is from FLY414, a different chart but this could be a hint to concentrate on or near the GPS module. This chart shows that the data simply stopped reporting and the GPS dropped out. Notice the gaps in the top graph. There are no reports for that period.

 

[rpm3]

hmmmmm........thanks Dawg, great information.....just not sure where to go from here....I suppose I can open it up and take a look....see if anything is physically, and obviously wrong, but my expertise is limited on the inside of this drone.....early on in my drone days, I modified, and added components to a Phantom 1, soldering no problem..blah blah blah...as long as I had concise instructions, usually with youtube video for help, ...but I suspect everything is more integrated now....and my repair options might be limited.

If I open 'er up, and there is nothing that is apparently wrong to me, and I still want to pursue repair, I bet I'll need to swap out the main board, or something like that.....I might find a used one for "cheap" (probably the best route to go) ....it would be good for me to learn more about it anyway.....

The weird thing for me, in my mind, it seems like electronics fail, or they don't, and unless its a simple bad/loose connection, they don't tend to heal themselves between many flights..only to fail again....intermittently....

 

[Fly Dawg]

and unless its a simple bad/loose connection,

Personally I would consider first either a loose connection, or in a more difficult situation and cracked trace and/or solder point. It seems to be intermittent and those are the hardest to find no doubt.

 

[3rdof5]

Personally I would consider first either a loose connection, or in a more difficult situation and cracked trace and/or solder point. It seems to be intermittent and those are the hardest to find no doubt.

Wouldn't a laser pointer that was hot enough to precision solder with be handy for that!

 

[Fly Dawg]

Wouldn't a laser pointer that was hot enough to precision solder with be handy for that!

Yes, but unfortunately trying to do that by hand would be next to impossible. Especially with an 5mil or smaller trace.