*** UPDATE ***
First of all, let me just comment that I think the whole situation with the Zenmuse H3-3D gimbal going limp was caused by hooking my DJI Phantom 2 up to my PC and running the DJI Assistant software (V3.0) and updating the Main Controller firmware to V3.04. I think something in this process (or the firmware) caused the H3-3D to no longer function...that's my opinion....your opinion is probably different...but I'm stickin' to mine!!
Well after two days of searching, reading and trying different solutions from the Internet forums about this issue, I am excited to report that I was able to bring my Zenmuse H3-3D back to life! Didn't think it was going to happen, but late this afternoon, I finally made it twitch!
How, you ask? Well, let's just say, I learned a lot about the different versions of the DJI Assistant software (versions 1.08, 2.00 and 3,00), the RC Assistant software, and the firmware 'update process' with the DJI Phantom 2 on my own. Thanks to all those that went before me though and posted their experiences, as well as videos for my educational process! It wasn't quite as scary knowing some of you had been down this path before. So, I really want to thank those involved in the solutions I found that worked for me.
I blindly followed people's advice, either in forums or via YouTube videos, in learning about the firmware upgrade process with the DJI Assistant and RC software. I must say, I'm not fond of the exact process for updating the various firmwares in the DJI Phantom 2. It seems a little haphazard to me and the relationship between one firmware upgrade and another was somewhat confusing at the beginning. (Still is, as far as that goes...) Not knowing that I needed to see the 'H3-3D IMU' listed in the upgrade window of the DJI Assistant software stifled me, until I read somewhere that I should be seeing that. That piece of knowledge led me to find the photo that Tahoe Ed posted in the RCGroups.com forum of the backplane of the H3-3D pins and the instructions to short two of them out to 'reset' the gimbal. I had initially tried that procedure, but evidently had failed in following the exact steps.
Well, this afternoon, I decided to try it one more time. It is a little hard to hold the backplane, a pair of tweezers and power on the Phantom 2 all at once, but I succeeded in doing it. When I finally got it, the gimbal's red & yellow light came on! Since I already had the Phantom 2 connected to my PC with the USB cable, I fired up the DJI Assistant software and selected the "upgrade tab". Lo and behold, there was the H3-3D IMU now showing in the listing of firmware. I selected it, went for the updated 1.0.0.6 version and performed it. It succeeded as "successful', so I cycled power on the Phantom 2 and all of sudden, the gimbal came to life!
I did some gimbal adjustments in the DJI Assistant software (V3.0) to verify everything was working, and it was! So, I disconnected from the PC and took her flyin'! SUCCESS! All is back to normal, with updated firmware on the Main controller (3.04) and the H3-3D IMU (1.0.0.6). Whew...glad that's over for now...No more firmware updates for me....at least for awhile!!!
Hope this helps some of you, if you have the same problem I did! GOOD LUCK!
P.S. The update process I mainly followed is here:
Originally Posted by Tahoe Ed in the RCGroups.com forum
Here is a reset procedure from DJI.
1. jumper the 2 dots in the picture below using tweezers.
2. power on phantom
3. remove tweezers when you see red and yellow LED on together.
4. connect to assistant software to re-upgrade.
