JoostBoZ Posted at 2017-1-9 05:15
Alright, by the looks of it, we have many Mavic owners with the same problem. Hence, maybe the following is a good summary of the problem, observed behaviour, possible cause and an interim / temp solution.
___________________________________

After using the Litchi app and not being able to reproduce the problem -- I also strongly suspect a software problem.

R&L Aerial  Posted at 2017-1-6 06:06
It should fly over snow, that shouldn't be an issue. There's something wrong with some mavics and everyone is trying to figure out why. Personally I think the problem lies with the DJI go 4 app.

R&L,  I'm sure you've been flying with Litchi for a good week or so now.    Have you had any repeat of the problem that you were having with DJI Go?   

I've done several flights with Litchi and it's working perfectly so far.

I sent in my mavic and without any explanation as to why, I'm having to use a DJI care replacement and pay the $79 deductible for a replacement.  Of course I experienced the VPS issue that everyone else is having but I also experienced the auto take off and immediately flying directly forward and all engines stopping at once, crashing to the ground from 4 feet, remaining powered on with no errors being displayed.  Now I know this is happening to others on the forums.  How this is my fault is beyond me as I didn't touch the sticks, I simply watched in shock as it just started going forward and instantly falling to the ground.  Does anyone have any idea why this would be my fault and would require me to use my DJI Care replacement to get replaced???

iPurvis Posted at 2017-1-10 01:33
@DJI-Ken

Should everyone experiencing VPS issues begin an RMA?

R&D is working on it, if you feel safer sending the aircraft in after verifying it is indeed an aircraft issue then feel free to contact support and start an RMA.

NomadRT Posted at 2017-1-10 09:20
R&L,  I'm sure you've been flying with Litchi for a good week or so now.    Have you had any repeat of the problem that you were having with DJI Go?   

I've done several flights with Litchi and it's working perfectly so far.

I have had 11 flights using litchi and not a single issue, this is why I'm not RMA at this time because I'm sure the problem is fixable with future updates.

JoostBoZ Posted at 2017-1-10 06:26
Would be indeed curious to hear whether all users with the same VPS problem are required to send in their Mavics. This would almost be the equivalent as a significant recall.

I'm still putting my hopes on the next firmware or app update to fix this issue.

Not ever close to a significant recall at all. There's tens of thousands of Mavics out there and it's a very small number or people who are experiencing this.
more than likely a firmware update will resolve it.

DJI-Ken Posted at 2017-1-10 09:30
R&D is working on it, if you feel safer sending the aircraft in after verifying it is indeed an aircraft issue then feel free to contact support and start an RMA.

Thanks for letting me know.

After todays performance form the mavic I'm gonna try a firmware downgrade tomorrow to see if this solves anything, I don't think anyone has yet tried this, Lots of drift, even had an issue with precision landing switched off, but only the once. Also a consideration is the Litchi app as some are reporting no issues using it. if the VPS problem is still obvious I'm going for an RMA or to swap it out with my u.k retailer.

R&L Aerial  Posted at 2017-1-10 09:31
I have had 11 flights using litchi and not a single issue, this is why I'm not RMA at this time because I'm sure the problem is fixable with future updates.

That is probably more that likely the case.
Let's see what happens in the next week or so.

iPurvis Posted at 2017-1-10 09:35
Thanks for letting me know.

After todays performance form the mavic I'm gonna try a firmware downgrade tomorrow to see if this solves anything, I don't think anyone has yet tried this, Lots of drift, even had an issue with precision landing switched off, but only the once. Also a consideration is the Litchi app as some are reporting no issues using it. if the VPS problem is still obvious I'm going form an RMA or to swap it out with my u.k retailer.

The aircraft should not drift, .that may be IMU or compass calibration procedure.
If you send it in please let me know and post your case# again.

DJI-Ken Posted at 2017-1-10 09:39
The aircraft should not drift, .that may be IMU or compass calibration procedure.
If you send it in please let me know and post your case# again.

Will do, thanks for your help

R&L Aerial  Posted at 2017-1-10 09:31
I have had 11 flights using litchi and not a single issue, this is why I'm not RMA at this time because I'm sure the problem is fixable with future updates.

I agree with you.   Some way the software is interpreting data from the craft.

NomadRT Posted at 2017-1-10 09:06
I can comfortably say that using Litchi seems to have solved the strange VPS/collision/auto land/drift upward issue that I was having.    I've done several flights now with no repeat of the problem.   I will now go back to DJI GO and see if I get a repeat of the problem just to triple check.

So you're able to fly problem-free with Litchi with all the sensor options enabled? Would you care to do a quick experiment to test a theory? With all the sensors enabled in Litchi, does the Mavic appear to implement any kind of downward OA or ground clearance safety measures? ie. Does it prevent you from flying closer than about 0.5m above the ground? Will the Mavic shoot up if you place your hand directly under it?

If the normal behavior in Litchi is to allow you to fly as close to the ground as you want, that could explain why it still flies normally even with a (possibly) faulty sensor.

BTW, are you on Android or iOS? I'm on Android and I plan to test this out with Litchi myself when I get a chance, hopefully within the next day or two.

iPurvis Posted at 2017-1-10 09:48
Will do, thanks for your help

No problem, let me know if the calibrations resolve it.

Jason Lane Posted at 2017-1-10 10:38
So you're able to fly problem-free with Litchi with all the sensor options enabled? Would you care to do a quick experiment to test a theory? With all the sensors enabled in Litchi, does the Mavic appear to implement any kind of downward OA or ground clearance safety measures? ie. Does it prevent you from flying closer than about 0.5m above the ground? Will the Mavic shoot up if you place your hand directly under it?

If the normal behavior in Litchi is to allow you to fly as close to the ground as you want, that could explain why it still flies normally even with a (possibly) faulty sensor.

I will test this today if I get home before dark.   Good suggestions.

I'm on iOS.   

I only experienced the vps error on the old firmware, since upgrading to latest firmware, I have had six flights without issue. I think the problem is software especially if running fine on another platform.

Im only sending mine back as i do not have visual module files and everyone else does. I too think this is a firmware issue. I think by sending my drone in will allow r&d to fix the issue quicker.

FlameBoy Posted at 2017-1-10 14:15
Im only sending mine back as i do not have visual module files and everyone else does. I too think this is a firmware issue. I think by sending my drone in will allow r&d to fix the issue quicker.

I notified beta team as soon as this happened to me and uploaded all the flight logs.

Hopefully a fix very soon.

I see a lot of people are saying it's an issue with the app, since the mavic is designed to fly even without the phone/tablet, will the VPS engage by flying with just the controller? Has anyone tried not connect the phone at all and see if it lands normally with VPS? Just some thoughts, I haven't receive my mavic yet but it looks like a very interesting problem and I am a little bit worried myself.

Jason Lane Posted at 2017-1-10 10:38
So you're able to fly problem-free with Litchi with all the sensor options enabled? Would you care to do a quick experiment to test a theory? With all the sensors enabled in Litchi, does the Mavic appear to implement any kind of downward OA or ground clearance safety measures? ie. Does it prevent you from flying closer than about 0.5m above the ground? Will the Mavic shoot up if you place your hand directly under it?

If the normal behavior in Litchi is to allow you to fly as close to the ground as you want, that could explain why it still flies normally even with a (possibly) faulty sensor.

Flying with Litchi, I could put my hand under the Mavic and it would rise away from it.

I have been hand catching and since the last update mine is rising with hand underneath

DJI-Ken Posted at 2017-1-10 09:35
That is probably more that likely the case.
Let's see what happens in the next week or so.

Hi Ken,

So to clarify, if I'm having the same issues, I can just sit patiently for a firmware update in the next couple weeks and don't need to send in my Mavic as R&D is working on a solution for all users and not just people who send in data and drones?

Thanks in advance for your response.

Bax Posted at 2017-1-10 19:44
I have been hand catching and since the last update mine is rising with hand underneath

That's strange. The Mavic's default behavior has always been to rise up if you tried to grab it from underneath, even in the first firmwares. I know because it surprised the hell out of me the first time I tried to hand catch it back in November :-)

Perhaps you've just been lucky and you've been unknowingly grabbing it just in front of the sensors?That's a known technique for hand catching it with the sensors still enabled. Or you forgot that you had the sensors disabled?

Jason Lane Posted at 2017-1-10 22:38
That's strange. The Mavic's default behavior has always been to rise up if you tried to grab it from underneath, even in the first firmwares. I know because it surprised the hell out of me the first time I tried to hand catch it back in November :-)

Perhaps you've just been lucky and you've been unknowingly grabbing it just in front of the sensors?That's a known technique for hand catching it with the sensors still enabled. Or you forgot that you had the sensors disabled?

It was rising previous firmware, but I am not sure how it behaved when I had the VPS error, you may be correct that I was hand catching avoiding the VPS by accident.

Now though after the new firmware and numerous hand catches, it definitely sees my hand and rises prior to land command.

ENT2019 Posted at 2017-1-10 20:55
Hi Ken,

So to clarify, if I'm having the same issues, I can just sit patiently for a firmware update in the next couple weeks and don't need to send in my Mavic as R&D is working on a solution for all users and not just people who send in data and drones?

They are working on it, if you don't want to fly the aircraft then you can contact support and send yours in for evaluation.

DJI-Ken Posted at 2017-1-10 10:56
No problem, let me know if the calibrations resolve it.

A few short flights today after an assistant 2 vps, IMU and compass calibration. Gusty winds today in the U.K. No drift to report, especially in the wind and had no VPS issue either.... all with precision landing, and VPS sensors on using go app 4 version 4.0.2

Tested the vps with my hand under the drone and it lifted away as it should and of course tries to fly off during a hand catch so all seems well today.

Next flights will be at the weekend where I'll have a bit more time to do a full run through again

iPurvis Posted at 2017-1-11 11:29
A few short flights today after an assistant 2 vps, IMU and compass calibration. Gusty winds today in the U.K. No drift to report, especially in the wind and had no VPS issue either.... all with precision landing, and VPS sensors on using go app 4 version 4.0.2

Tested the vps with my hand under the drone and it lifted away as it should and of course tries to fly off during a hand catch so all seems well today.

Thank you for reporting, i'm sure the IMU and compass calibration resolved the drift.
But strange that you had no VPS issues.
Some others have tried calibrations including the sensor calibration from the Assistant2 and it was the same.
Let me know how it goes over the weekend.

After experiencing this VPS issue for some time I sent my Mavic to DJI. Today I received a notification that they were replacing a logic board on my aircraft. So to me it sounds like this VPS problem must be a hardware issue.

NomadRT Posted at 2017-1-10 19:34
Flying with Litchi, I could put my hand under the Mavic and it would rise away from it.

My very quick test with Litchi on my Android agrees with yours; with all sensor options enabled in Litchi, the Mavic stopped descent at around 0.5m from the ground, and also rose up away from my hand as I reached up to it.

BTW, does Litchi on iOS also give you the option to enable/disable "Landing Protection?" I noticed it in Litchi on my Android today. I understand it's not present in the iOS Go4 app, but I wonder if it's there in iOS Litchi. And if it is there, I wonder what happens if you turn it off in Litchi, and then switch over to Go4. Would you effectively have Landing Protection disabled, and still get full VPS and Precision Landing in Go4?

Delsonrus Posted at 2017-1-12 04:26
After experiencing this VPS issue for some time I sent my Mavic to DJI. Today I received a notification that they were replacing a logic board on my aircraft. So to me it sounds like this VPS problem must be a hardware issue.

The problem is that my issues vanish when using Litchi.    If it's hardware that wouldn't happen.

I flew it a couple of times earlier.  The first flight was terrible, and every single time I tried to descend it went into landing mode.  Almost impossible to get it to descend at all, just kept showing clearance at 0.1-0.2m.  I eventually landed it.

Tried another flight immediately after in exactly the same area, and it flew perfect.  Not one single instance of forcing into landing mode on descent.  

Absolutely no idea why the first flight was so bad, and the second flight (immedaitely afterwards) had no issues whatsoever.  Both flights were in the DJI GO 4 app.

I've just purchased litchi.  Did one flight with it after and it was fine, but will need to test it a bit more to see whether it makes any diff.

I'm still completely unsure whether this is firmware or hardware prob.  Since purchasing my mavic I've been affected by this problem on every session, it's really annoying as it feels like my control inputs when descending are being repeatedly overridden by the auto landing mode.  

Did a flight today with the precision landing turned off and seemed to fly well. Still did the hover when it got back to the landing spot and had to "tell" it to land. Overall seemed normal.

NomadRT Posted at 2017-1-12 06:37
The problem is that my issues vanish when using Litchi.    If it's hardware that wouldn't happen.

Do you think an app can affect Mavic? What if you try flying without any app at all? In this case I suppose Mavic also should not experience any problems with VPS sensors either. If that's the case then I will agree it's a software issue.

Delsonrus Posted at 2017-1-12 04:26
After experiencing this VPS issue for some time I sent my Mavic to DJI. Today I received a notification that they were replacing a logic board on my aircraft. So to me it sounds like this VPS problem must be a hardware issue.

Just wondering when did you send your Mavic in/DJI received it?

I am having a bit of a nightmare with DJI RMA process...
I sent in my Mavic and DJI recieved it a week ago.

Via live chat:
Monday support said they got it and will be fixing it
Tuesday - good news they are replacing the whole unit and should arrive Thur/Friday
Wednesday - can't get details prob with site
Wednesday night - they need to evaluate not sure eta
Thursday - not sure of the status, need 1 - 2 weeks

I don't know what is going on here, why the first few agents made it sound like everything is going smoothly, and then the subsequent agents don't know what is going on and are suggesting it is taking long

@DJIKen and Mindy - can you please help me with my case? If you can look it up (I can PM you the case #)

WilliamDJI Posted at 2017-1-12 21:44
I am having a bit of a nightmare with DJI RMA process...
I sent in my Mavic and DJI recieved it a week ago.

If you want to catch Ken's attention more quickly, you should reply to one of his posts so he'll get an immediate notification.

WilliamDJI Posted at 2017-1-12 21:40
Just wondering when did you send your Mavic in/DJI received it?

I sent it a week ago and they received it on 11th. Did they get yours?

WilliamDJI Posted at 2017-1-12 21:44
I am having a bit of a nightmare with DJI RMA process...
I sent in my Mavic and DJI recieved it a week ago.

Live chat is horrible and they lie constantly

Delsonrus Posted at 2017-1-13 04:26
I sent it a week ago and they received it on 11th. Did they get yours?

Thanks for the reply

I sent mine in late Dec and they received it on Jan 6 (DJI California)

Very frustrating as at first it seemed that everything was moving along, and then the last two reps made it sound like no progress. Either the first few were lying or the last few... :s
When you look up yoru case status online, what stage is it at?
Also did they email you that they are changing the logic board? or did you call them/live chat to get this info?

Thank you!

Jason Lane Posted at 2017-1-12 22:13
If you want to catch Ken's attention more quickly, you should reply to one of his posts so he'll get an immediate notification.

Thanks Jason! Good point!

DJI-Ken Posted at 2017-1-11 12:06
Thank you for reporting, i'm sure the IMU and compass calibration resolved the drift.
But strange that you had no VPS issues.
Some others have tried calibrations including the sensor calibration from the Assistant2 and it was the same.

DJI-Ken, I am hoping you can help me with my case (see my post above please)

DJI received my Mavic that I shipped late last month - first few chats with reps made it sound like everything is moving along and they are sending a replacement
Last two reps via chat are now telling me no updates and it'll be another 1 - 2 weeks before I hear back

Everytime I nearly wait an hour to speak to a rep via live chat, and connected with 5 - 6 reps...all different updates.