Yaw snap after ribbon cable issue

[jcknows0]

I've read on other forums people having this issue but see nothing on this forum. I was hoping to search the collective knowledge base as to the best way to handle the yaw snapping issue with the H3-3D. I've seen that it will often reset itself to center and the buzzing and snapping will stop. I've tried recalibrating (it stops momentarily), resetting (a giant pain) and testing all the motors while off (does not seem to be failed). The main problem is this is uncontrolled so even turning on the motors will reinitiate this problem. It basically makes any video obtained untrustworthy and difficult to shoot reliable video. Thankfully its on my 2nd "spare" Phantom but I was hoping to use it more to give my main rig a rest. I'm grounded right now due to this lovely nor'easter weather so any help would be greatly appreciated.
I see some rather drastic actions as well as minor (turning on phantom while pointing true north which does nothing) but I take this site as the experts.

 

[QYV]

you mentioned that your H3-3D buzzes fairly loudly when it's just sitting there, yes? I was having a similar issue, my h3-3d made a lot of noise just trying to look "straight ahead" and when I would fly... constant yaw snaps which are actually when the gimbal gets so far out of whack it gives up (goes limp) then resets... the same thing will happen if you fiddle with the gimbal while it's running.

anyway, I solved my issue by making sure the setup was neutral balanced. There is apparently quite a bit of variation in the production of the H3-3Ds, some are perfectly balanced from the factory and others are off. The buzzing/humming from the motors just looking ahead are the motors having to work hard just to point it ahead.
Neutral balance is when, with the power OFF, you can position the gimbal pointing straight ahead, let go and it basically stays in place or moves just a tiny amount. If the gimbal drops hard to any direction.. side, forward, whatever... then it is NOT neutral balanced.

I suggest you check out this post I'm linking below... in it I mention neutral balance and link some videos I made showing my version of the issue and how I fixed it.
viewtopic.php?f=19&t=33255&start=10#p306882

 

[jcknows0]

Perfect, thanks for the quick response! I've had a feeling it was an issue similar to that, and yes I confess my gimbal is off balance (unlike its predecessor which never gave me a problem once I figured out the bricking issue). Not sure if I should try the coin trick, but I'll definitely try this fix.

 

[QYV]

Perfect, thanks for the quick response! I've had a feeling it was an issue similar to that, and yes I confess my gimbal is off balance (unlike its predecessor which never gave me a problem once I figured out the bricking issue). Not sure if I should try the coin trick, but I'll definitely try this fix.

it doesn't have to be a coin per se, just any kind of counterbalance. for example I cut tiny pieces of gaffer tape and stacked them, you can stick them anywhere and they don't really hurt anything

 

[jcknows0]

Thanks I actually got it on first shot, and it has definitely fixed the problem. If I turn too quick it might yaw snap once up in the air but then it rights itself. I can live with this as I have the off center camer/leg problem anyway while flying so I'm pretty conservative in my speed. Thanks as I was not aware the balance could cause an issue so severe.

 

[jcknows0]

Actually the problem is back in full force. I'll try recalibrating and see if that helps now that I've added the coin. I also did a compass calibration after the only mostly problem free flight (maybe this caused it to return?). I didn't have this problem until a tear in the ribbon cable caused this issue with the gimbal. I thought after I replaced it everything would be good again but this problem won't seem to go away.