Hello,

On an S900 (A2, Lightbridge, Zenmuse) we experience problems with the spreading wings. I think it happened after we upgraded to the latest firmware of the A2. (all other firmware are up to date).

Whenever I power up the drone the left right spreads open about 2-3 cm and then 2 seconds later comes back to its original position.

Then when spreading the wings with the switch on the transmitter, same kind of thing happens: meaning it opens 2 cm then opens completely. Same when coming down, closes to 97% and then after 2 sec closes completely.

Problem is that the right leg somehow becomes erratical in it’s behaviour. On 2 occasions  the right leg went up on it’s own without moving any switch.

So we tried to recalibrate the spreadings wings, but the recalibration fails and the yellow stays on after the procedure.

When we power again the drone, the light becomes green. But we still have the problem of the strange behaviour of the right leg.

We uploaded a video that shows the problem::

Thank you so much for feedback/advice.

Eugene

Could you clarify what firmware you were on before and what you have currently on the unit? Are there any additional troubleshooting steps you have done thus far besides what was mentioned?
Edit:
In addition, I would like for you to check the springs on your landing gears to ensure that they measure at 70mm in length. It is more likely that the springs are either too tight or not tight enough.

Hello Jamie,

Thank you for your response.
I do not know what version of the firmware was before the update (I recently bought it second hand).
Here are the actual version number:
Main controller > 2.7
IMU > 2.5
LED > 2.1
Receiver - 2.4 > 1.1
GPS Pro+ >2.6
Gps Module+ 2.6

I checked the spring and they were at +/-  7,3 cm (from top to bottom of spring). So I modified it to 7 cm but that does not resolve the problem.

I uploaded a second video so that you can see it even more clearly:


Thx for your follow-up on this.

mail@eugene-her Posted at 2016-9-1 02:29
Hello Jamie,

Thank you for your response.

Are you able to calibrate the landing gear, or does that still remain unresponsive?

mail@eugene-her Posted at 2016-9-1 02:29
Hello Jamie,

Thank you for your response.

I have had this same exact problem for 2 years...I have gone through 4 different landing gear assemblys and still the same. DJI Adelea said it isnt an issue but I think it is...let me see if I can find my posts on it.

dennismurry08@c Posted at 2016-9-2 22:45
I have had this same exact problem for 2 years...I have gone through 4 different landing gear asse ...

I took the video down to give me space on Vimeo account but here's the thread...I have not resolved this. I did the RMA like 3-4 times and they were all the same with the same issue as you. If needed I could take another video and post but since your's is up then its just going to be a duplicate. http://forum.dji.com/thread-47706-1-1.html

Having the landing gear move without any input is disconcerting, however the actual raising and lowering of the landing gear seems to be within a reasonable range. If the landing gear still wont attempt to calibrate, then a RMA for further diagnostics would be recommended.

DJI-Jamie Posted at 2016-9-3 01:56
Having the landing gear move without any input is disconcerting, however the actual raising and lowe ...

Jamie, I did the RMA and it was either 3 or 4 of them total...all the replacements did the same exact thing. There were a couple of tickets, 281741, 287883. I received 2 new units and they did the same thing so I just gave up...You want a video? Its basically the same as the one thats already posted...I believe its a mechanism issue but nobody believed me. The other problem is they do not raise evenly..one side raises faster than the other side and also going down.

dennismurry08@c Posted at 2016-9-3 03:21
Jamie, I did the RMA and it was either 3 or 4 of them total...all the replacements did the same exa ...

Have you checked the length of the springs on your landing gear to see if they are overtightened or under tightened? Either scenario can cause strain to the servo.

DJI-Jamie Posted at 2016-9-3 05:28
Have you checked the length of the springs on your landing gear to see if they are overtightened o ...

of course...it isnt the springs...the gear will go up...stop...then go up some more...Adela thought it was internal wear but I had 4 different assembly's that did the same thng...I even tried cheating on the end points with the servo but that didnt work either. I also had the same exact problem with calibrating as Mail points out. I had a detailed video that your service has seen there in LA and in fact one of the Techs called me about it and sent me an assembly to try...I did a video of that also doing the same thing...that said I can vouch for 5 assembly's doing this....for me I have 4 left side and 1 right side. Hope this gets looked at as it looks like others are discovering it now. BTW, this issue goes back a ways when I first pointed it out.

Hello Jamie,

Sorry for my late follow-up.
After having the springs adjusted I still have no possibility to calibrate the landing gear.
What does it mean when you say it might need an RMA?

mail@eugene-her Posted at 2016-9-10 18:07
Hello Jamie,

Sorry for my late follow-up.

You have to call support and explain the problem. They will email you a number to return the faulty part and where to send it. The number is called an RMA or return authorization. You cant send anything in for repair without an RMA. It does NOT guarantee the return will be repaired under warranty. It just means you send it in and they will either replace it or tell you how much it's going to cost. Note, for these landing gear assembly's, they do not repair...they only replace.  Hope this helps

mail@eugene-her Posted at 2016-9-10 18:07
Hello Jamie,

Sorry for my late follow-up.

It's as dennismurry08 indicated. The next course of action would to contact the Europe Support Center to have the unit sent in for further diagnostics.

This may not be the answer but I had a gear problem on two separate occasions, the cause of which was only discovered by close inspection of the linkage screws. on each occasion it was found that one was missing and caused the legs to jam, usually in the up position. Make sure all your screws are in and secure.
Worth a try.....!

OK Thank you Jamie and Dennis and Safron96 for your feedback.
Will also check if all the screws are in position.

mail@eugene-her Posted at 2016-9-17 20:22
OK Thank you Jamie and Dennis and Safron96 for your feedback.
Will also check if all the screws are  ...

Please keep us posted.

Thank you all for yours answers!
I did indeed check the spring and did a micro change (3mm) on the length of the springs.
It seemed to have resolved the problem, though the legs still go up in a staccado way (not smooth)

More recently I had a problem again with one of the legs that did not want to go up.
After an intense check I found a little S hook (used to hang the drone on the ceiling) that probably fell during one the maintenance check and attached itself close the mechanism of the leg…
That solved the problem…