[SOLVED!!!] - IMU ACC1 shows "Data Error" - AC has never suffered a crash or anything similar.

[Deleted member 94047]

Hi, I was following the thread with great interest. I use MEMS sensors in my work and I suppose the IMU is just a type of MEMS accelerometer. Now personally I don’t have experience with an accelerometer but I do have experience with MEMS charged plates that exhibit stiction issues from time to time. When you mention that your drone was subject to shocks, it comes together to me that your sensor could be suffering from stiction too.

Reference

if you read some of the published materials about accelerometer sticition in certain axis as above link, it also mentions that the same shocks can free the members from stiction. Now how much shock? That is a great question. My guess is if you have already opened up your main board and expose the IMU module, a gentle tap with your index finger should be enough. If all else fails now it seems a replacement of the imu module sourced from the internet is a good idea.
Do let us know what you decided to do.

Great info! Thanks a lot @lee82gx. I haven't yet opened up the MA; I am making that a last resort. I flew two batteries with it earlier today and it performed as it should. For now, the one working IMU seems to be perfectly adequate and I will continue to research what I can do to fix the accelerometer of the other that seems to be stuck. And hence why I greatly appreciate the info you provided. It makes sense that a shock can return the accelerometer back to a functional state and I am pondering how best to provide that shock. Another bike ride with the MA hanging from the handle bars? A whack on its behind? A few hard maneuvers in sports mode - such full throttle followed by a full break? Like you said, how much shock? is the question.

 

[Prismatic]

Great info! Thanks a lot @lee82gx. I haven't yet opened up the MA; I am making that a last resort. I flew two batteries with it earlier today and it performed as it should. For now, the one working IMU seems to be perfectly adequate and I will continue to research what I can do to fix the accelerometer of the other that seems to be stuck. And hence why I greatly appreciate the info you provided. It makes sense that a shock can return the accelerometer back to a functional state and I am pondering how best to provide that shock. Another bike ride with the MA hanging from the handle bars? A whack on its behind? A few hard maneuvers in sports mode - such full throttle followed by a full break? Like you said, how much shock? is the question.

Percussive maintenance is a black art, and seductive.
You slap the TV and it starts working again. Next thing you know, you're giving the furnace a swift kick, and hey presto! the house warms up.
Then one day the oven won't unlock after a self-cleaning cycle, but your magic is too strong, and you have to explain to your spouse why the oven door won't close right anymore.
?

 

[Deleted member 94047]

Well, well, well ... what do you know!. I can't believe a good old fashioned slap fixed it!

I came across this post at the DJI Forums from five years ago; It is about the Phantom 3 Pro but I read on. And then there was this particular post which explained where exactly one should slap the AC based on which value is stuck on what axis. And I gave it a try. It took me two attempts but it sure is fixed now.

This is what Assistant 2 was reading from the two IMUs before the tap; note the values of the two accelerometers on the X-axis.


And this is what it read after the second tap; the accelerometer on IMU 2 is no longer stuck on 16


And this is after calibrating the IMU


And this in the GO4 sensor state .... no more "Data Error"!


A big thank you for everyone who helped!!!!!!!

 

[lee82gx]

Well, well, well ... what do you know!. I can't believe a good old fashioned slap fixed it!

I came across this post at the DJI Forums from five years ago; It is about the Phantom 3 Pro but I read on. And then there was this particular post which explained where exactly one should slap the AC based on which value is stuck on what axis. And I gave it a try. It took me two attempts but it sure is fixed now.

This is what Assistant 2 was reading from the two IMUs before the tap; note the values of the two accelerometers on the X-axis.
View attachment 88949

And this is what it read after the second tap; the accelerometer on IMU 2 is no longer stuck on 16
View attachment 88951

And this is after calibrating the IMU
View attachment 88952

And this in the GO4 sensor state .... no more "Data Error"!
View attachment 88953

A big thank you for everyone who helped!!!!!!!

Can you confirm for us that x axis is front back for Mavic air? For the phantom the shape is confusing for me since it’s symmetrical front and side.

 

[lannes]

There you go , a good ol whack fixed it LOL

 

[Deleted member 94047]

Can you confirm for us that x axis is front back for Mavic air? For the phantom the shape is confusing for me since it’s symmetrical front and side.

In my case, yes it was the front as the x axis was stuck at a high +.

 

[Deleted member 94047]

You were right all along

There you go , a good ol whack fixed it LOL

 

[lee82gx]

Two wrongs make one right!

 

[silverdragon]

The Mavic Air Service Part - IMU Module gave me data error I repaired it myself. It was very easy to do. Patience was the key factor in getting it done. Just make sure when it's time to reconnect the connectors to the board they are lined up before pressing them down....I just finished testing the Air out...Changing that part out was the only way getting rid of the data error.

 

[hrishishah]

Hello All...I own a Mavic Air and 4 months back it fell a little by hitting a branch at a height of 1 and 1/2 feet approx...Then I started getting the IMU Calibration and Data Error and drone was not taking off...I went through tons of forums and tried to see what can be done to fix the error...nothing worked. I bought a DJI Mavic Air 2 and started using that...which is really good. It did have some issues with 4k / 60 hz but figured out later that it is an apple OS issue...I upgraded my laptop which came with Big Sur and it magically worked seamlessly.

So coming back to the Mavic Air...Today I finally wanted to give it a last try to make it work...I tried to calibrate a couple of times but did not work...so took it out...Picked it up and dropped it horizontal from height of 1 feet and you will not believe it magically started working like before...Looks like it moved back the IMU which might have moved due to the earlier impact.

So all said and done...now I have 2 good drones...cross my fingers...
Hope this helps...

 

[lannes]

Hello All...I own a Mavic Air and 4 months back it fell a little by hitting a branch at a height of 1 and 1/2 feet approx...Then I started getting the IMU Calibration and Data Error and drone was not taking off...I went through tons of forums and tried to see what can be done to fix the error...nothing worked. I bought a DJI Mavic Air 2 and started using that...which is really good. It did have some issues with 4k / 60 hz but figured out later that it is an apple OS issue...I upgraded my laptop which came with Big Sur and it magically worked seamlessly.

So coming back to the Mavic Air...Today I finally wanted to give it a last try to make it work...I tried to calibrate a couple of times but did not work...so took it out...Picked it up and dropped it horizontal from height of 1 feet and you will not believe it magically started working like before...Looks like it moved back the IMU which might have moved due to the earlier impact.

So all said and done...now I have 2 good drones...cross my fingers...
Hope this helps...

Nothing that a good whack doesn't fix

 

[swadeky]

So after reading through the thread which BigAl linked in post #2 above and watching a few Mavic Air tear-down videos on YT, I am going to have a go at opening mine too see if resetting the IMU ribbon cable can fix this error. But before I go ahead and do that, I would love to hear from people in the know regarding:

(1) Is it perhaps better to leave it as is - with just one functioning accelerometer? There are no other errors other than the data error on one of the accelerometers and IMU state shows "Normal" on the system status page that appears immediately after I tap GO FLY. So should I open it up OR should I just leave it be? (Note - I have a mild case of essential tremor on both hands and do struggle with delicate tasks. I am really not looking forward to opening up the MA if I can help it, but if I have to, I will).

(2) If I have to open up the MA - where exactly is the IMU ribbon cable located? I can see the IMU module is located on the underside of the main board (the black, box like housing you see in the pics below) but I can't see where the ribbon cable is from the pictures I have found so far. If any one has experience doing this or a better picture, I would greatly appreciate any pointers.

Many thanks in advance.
View attachment 88558View attachment 88559

P.S> Please note that sending the AC to DJI or a repair shop are not options I have owing to my current location.
And I wish those of you who celebrate Christmas and New Year this time of year a very joyous holiday and a very happy new year!

I read through this thread, it seems like no one really answered the question if it is okay to fly with one functioning accelerometer!? Any thoughts? I have the same problem, one has a "data error", but overall it seems to fly okay? should I replace the IMU or is it fine? thanks!

 

[lannes]

I read through this thread, it seems like no one really answered the question if it is okay to fly with one functioning accelerometer!? Any thoughts? I have the same problem, one has a "data error", but overall it seems to fly okay? should I replace the IMU or is it fine? thanks!

It should be fine but you won't have any redundancy if there is a problem with the single IMU, many DJI drones only have one IMU by design and fly fine.