H3-3D Gimbal was acting funky, then went "bonkers" for lack of a better term. B&H Photo took the gimbal back and sent me a new one Hurray!
Installed, upgraded all firmware and this one also is not behaving.

So, my question: Is the controll for the gimbal on a board in the Phantom? Could it be the Phantom that is the problem and not the gimbal? Two gimbals gone wacky makes me question whether its not something else.

I have tried calibrating, advanced calibration, disconnecting the 2.4gh GS air end to reduce possible complications in troubleshooting.

Do you think it is likely or possible my Phantom is the problem?

Thanks for all your help. This forum has been great in getting me through some of these issues.

I have 2 different HD-3Ds and both work great. What do you mean by bonkers? Is it constantly twitching? Nonstop or only during start up?
Is the Gopro installed? Anything blocking movement?
Maybe post a video if you can.

Can you upload a video so that we can understand better what your problem is.

First one I returned, so, I have no video. Could not get it to point forward no matter how many ways I adjusted the sliders in the PT2 assistant. Made a horrible screeching noise, camera kicked left every few seconds in flight, gimbal control slowly eroded to almost nothing.

This Gimbal seems normal except the tilt. It is either all the way to one extreme or the other. I can adjust the limits fine, but there is no in between. As I slide the lever on back of the remote control, there is no gradual movement, but there is a point where it will tilt full up or full down. There is no way to get any "in between" no matter how slowly I move the lever.

All firmware is updated on Phantom and remote.
Calibration done.
Advanced calibration done.
Power cycled both the remote and the Phantom multiple times. Even tried power cycling after gimbal adjustments in the PT2 assistant. No luck.   

I really need to know if it is possible that the Phantom is at fault. If so, there is a chance I may be able to talk B&H into replacing the entire unit. But it needs to be done ASAP! time is running out!

Hi Gamecatcher,
Firstly I apologize for what you've been through with the Phantom recently.
Can you please help to check
1. If there is any damage on the vibration absorbers?
2. If the vibration the Phantom brought itself is strong enough?
You can return it to us so that we can have a double check if there is any obvious abnormal sound of gimbal.

Update ... now I am really frustrated with this P2!

Returned Phantom and H3-3D gimbal since the other one was not responding properly to the controls.

Pulled out new Phantom, hooked up new gimbal. Updated firmware first thing for both RC and Phantom. Did calibration, then advanced calibration.

Everythig is working wonderfully! Yeah! I finally have a functional gimbal. Started playing with the settings on the gimbal to control how fast the pan tilts, how far etc. Everything is reacting as it should to the new adjustments ... and then, the gimbal's controlls slowly started to erode. It started doing exactly what the other one did.

When sliding the lever on the back of the remote, the gimbal is supposed to tilt up and down. The three sliders on the PT2 app control how far they tilt. As I am adjusting the sliders, all of a sudden its response became eradic. I power cycled the Phantom, the RC and even the app. Restrated the Macbook and nothing has fixed the problem.

Specifically, the gimbal is now only responding to the lever in a very tiny range, so small it is impossible to controll it now. The majority of the movement of the lever does absolutely nothing, then all of a sudden, within a tiny range of movement, the camera will simply nod once and return to the original position.  

I have not even put the props on this Phantom. Neither the Phantom or the gimbal has ever left the ground, so I think we can rule out "crash induced issues".

I have a video. I'll post it if I need to. It's kind of long and tedious, but shows the issue.

But first, does this sound familiar to anyone? What can I possibly do to fix this?

I am so disgusted now, I want to return everything and just forget about it. I have the Groundstation hardware that I have not even installed on the unit yet. I'm $1600 into this (not counting GoPro) and still don't have anything that I can use.

Gamecatcher Posted at 2014-12-3 09:44
Update ... now I am really frustrated with this P2!

Returned Phantom and H3-3D gimbal since the ot ...

Try to calibrate Transmitter x1 channel

Check your gimble tilt and control gain is a 4 and the others at 0. When I got my P2 I set them all to 0 and had similar issues. Hope this helps.

I've had that problem too, more than once, and each time I resolved it by calibrating in RC Assistant, followed by calibrating in the Phantom Assistant.  Sometimes it requires repeating that sequence be for it works.

When you calibrate the gimbal lever, make sure you cycle that lever back and forth as part of the calibration process. The instructions don't make that clear.

Looks like all you need to do is to calibrate X1 Channels. Make sure you check BASIC on the RC tab. A picture or video of the problem and your settings would totally help the diagnosing and problem solving process so much easier.