DJI Phantom 2 Losing Altitude

[edurojma]

Hi guys, I've been struggling with my phantom 2 for weeks now, trying to get him up and running again.
After having an accidental crash, I replaced all the motors because either they were sounding differently or the props where not easily inserted on them, so I decided to change them all. During this process I accidentally dropped some solder in a ESC board (Yeah, I'm that lucky), so I ordered a couple of them.
The new ESC board came with version 2.1 while the others are version 2.0 I believe, (they don't say 2.1 on the front sticker like the new one says)
Well after making this change I decided to try it out, I first calibrated the compass as usual, which according to the lights it was calibrated, but then I couldn't get any GPS signal after waiting for a while, but I decided to test it anyway just to see if it was working fine. The end result is shown in this video:
http://youtu.be/ZomipXZcNcg

After initial lift off, everything seem to be working fine, there was a little wind but nothing important, but after only a few seconds it immediately lost altitude and dropped down drastically. Ended losing another 2 props and 2 prop guards because of it.
I decided then to check the GPS board and found out the ceramic part was broken, so I odered a new one and got it replaced, got the GPS signal back.
I also tested out the RPMs from the motors using a Laser Tachometer, they were all giving me around 2800RPM, I'm not sure if the guys who tested them out was doing the test right though, because he didn't test them with the props on.
Anyway, after the GPS was back on I decided to give it another shot, but the same altitude problem arises. I even noticed that it starts to turn by itself too, not so much, but it does.

I emailed DJI tech support, which told me to send the unit for repair. I'm not from the US so it's not that easy. They said that it can be related to the different ESC version installed. I already ordered as ESC v2.0 (hopefully) and will try to replace the v2.1.
I was wondering if anyone else has experienced this before and if it is in fact an ESC problem.
Thank a lot for any replies!
Regards.

 

[Hughie]

Hi guys, I've been struggling with my phantom 2 for weeks now, trying to get him up and running again.
After having an accidental crash, I replaced all the motors because either they were sounding differently or the props where not easily inserted on them, so I decided to change them all. During this process I accidentally dropped some solder in a ESC board (Yeah, I'm that lucky), so I ordered a couple of them.
The new ESC board came with version 2.1 while the others are version 2.0 I believe, (they don't say 2.1 on the front sticker like the new one says)
Well after making this change I decided to try it out, I first calibrated the compass as usual, which according to the lights it was calibrated, but then I couldn't get any GPS signal after waiting for a while, but I decided to test it anyway just to see if it was working fine. The end result is shown in this video:
http://youtu.be/ZomipXZcNcg

After initial lift off, everything seem to be working fine, there was a little wind but nothing important, but after only a few seconds it immediately lost altitude and dropped down drastically. Ended losing another 2 props and 2 prop guards because of it.
I decided then to check the GPS board and found out the ceramic part was broken, so I odered a new one and got it replaced, got the GPS signal back.
I also tested out the RPMs from the motors using a Laser Tachometer, they were all giving me around 2800RPM, I'm not sure if the guys who tested them out was doing the test right though, because he didn't test them with the props on.
Anyway, after the GPS was back on I decided to give it another shot, but the same altitude problem arises. I even noticed that it starts to turn by itself too, not so much, but it does.

I emailed DJI tech support, which told me to send the unit for repair. I'm not from the US so it's not that easy. They said that it can be related to the different ESC version installed. I already ordered as ESC v2.0 (hopefully) and will try to replace the v2.1.
I was wondering if anyone else has experienced this before and if it is in fact an ESC problem.
Thank a lot for any replies!
Regards.

I had one of the original P2 V2s with the v2.0 ESCs which were not labelled with any version on the white label, but they came along with the new 2312 motos and it all worked fine. I let my son do a landing and he did it fine but did not kill the motors (bad instructions from my part) and it tipped over and blew an ESC. When I ordered a replacement it was a 2.1 (said so on the white label). I questioned mixing ESCs with my supplier who told me it would be fine. I replaced blown ESC and flew about 30 flights with 3*v2.0 and 1*v2.1 without any problems at all.

 

[phantomlova]

check your 'gain'

 

[FedeVision]

Did you perform an advanced IMU calibration? If not, that could help.

 

[jason]

I had one of the original P2 V2s with the v2.0 ESCs which were not labelled with any version on the white label, but they came along with the new 2312 motos and it all worked fine. I let my son do a landing and he did it fine but did not kill the motors (bad instructions from my part) and it tipped over and blew an ESC. When I ordered a replacement it was a 2.1 (said so on the white label). I questioned mixing ESCs with my supplier who told me it would be fine. I replaced blown ESC and flew about 30 flights with 3*v2.0 and 1*v2.1 without any problems at all.

There has been some controversy over ESC board version numbers over the past few months. Seems it really doesn't matter whether what version P2 NV you may have they both use the same ESC v2.1 module. This is probably the same for the P2 vision line as well.

 

[edurojma]

I already did the Advanced IMU before, but I'll give it another shot.
The "check your gain" thing, can you be a little more specific?
I'll be posting another video soon so you can see the behavior from outside the Phantom 2.
Thank you all for answering.

 

[edurojma]

Hey guys, so I ordered other ESCs, they all came saying version 2.0 on the box but 2.1 on the sticker inside, so I ended up changing all the ESCs from the Phantom. I also connected it and clicked on the advanced calibration to see if it would help, however the issue remains. I think is something to do with the compass or something like that. I have uploaded another video that you can clearly see this behavior. Hope someone can help me out on this, I'll really appreciate it! Thanks

 

[TeamYankee]

Well, the altitude is controlled by the on board barometer - anyone know where it is inside the Phantom - could it be blocked or faulty?

 

[Hughie]

Sounding more and more like IMU

Edit: If you had a telemetry down link or Flytrex it would be interesting to see if the craft thinks its altitude is stable.

 

[N017RW]

Well, the altitude is controlled by the on board barometer - anyone know where it is inside the Phantom - could it be blocked or faulty?

It's part of the IMU located in the Naza.

http://wiki.dji.com/en/index.php/IMU

 

[TeamYankee]

In that case it looks like an IMU issue..
Btw. Flytrex has it's own barometer... so it would show the Phantom going up and down anyway.

 

[Hughie]

In that case it looks like an IMU issue..
Btw. Flytrex has it's own barometer... so it would show the Phantom going up and down anyway.

Yes good point.