Phantom 3 Pro IMU won't calibrate without gimbal board connected

[edmundC]

Crashed my P3P am trying to repair it. Something i found strange is that I couldn't calibrate the IMU when the gimbal top board ribbon cable is disconnected from OFDM board. Can anyone explain why is it so? I'm trying to learn as much as possible about my AC. Thanks in advance for enlightenment.

 

[quaddamage]

For learning - remember to check here:
o-gs/dji-firmware-tools

Especially the repo with schematics (linked in some of the above wikis) will be helpful.

I couldn't calibrate the IMU when the gimbal top board ribbon cable is disconnected from OFDM board.

That is strange, I don't know the reason for this. As long as OFDM is connected to ESC Center Board, it should start calibration. Though I never tried calibrating IMU without the gimbal in place. Try connecting front USB to a PC and checking if the packets there contain any message explaining the cause. Packets are binary, but some of them contain unencrypted text messages - so you should be able to see something even if you just use a simple terminal app to just put the data on screen.

 

[edmundC]

For learning - remember to check here:
o-gs/dji-firmware-tools

Especially the repo with schematics (linked in some of the above wikis) will be helpful.



That is strange, I don't know the reason for this. As long as OFDM is connected to ESC Center Board, it should start calibration. Though I never tried calibrating IMU without the gimbal in place. Try connecting front USB to a PC and checking if the packets there contain any message explaining the cause. Packets are binary, but some of them contain unencrypted text messages - so you should be able to see something even if you just use a simple terminal app to just put the data on screen.

Hi Quaddamage, thanks for your advice. I've never connected AC to a PC via USB port but I assume it's straight forward. I will try it tonigt and update the result.

 

[edmundC]

For sharing, I replaced a new P3P shell and test fly it just now and it flew with no problem. Note that I connected the gimbal top board to OFDM but i disconnected the flexi flat ribbon cables to the roll and pitch circuit boards (because it keeps making crazy 'dance' after power on). I managed to take off and fly the AC without problem but a 'No image transmission' msg keep popping up on Go app screen asking if I want to return home

 

[edmundC]

I connected my P3P AC to a PC to retrieve the .DAT files via USB port, used Airdata and CSV viewer to open the files and there are alot of data that I couldn't understand anyway I have replaced the gimbal top board and the flex flat cable now it seems working no more crazy gimbal dance, good video transmission and gimbal control all OK. Tomorrow will bring it for a test fly and hope everything is fine