My gimbal's ribbon cable broke, so I replaced it and now when I turn it on the gimbal does the initialization movements and can be controled using the controller, but goes limp after a few seconds. Anyone know what's up? I can't connect using the app because, I think, my GL300A controller's USB board is messed up, so I can't update firmware that way or find out any errors. I've tried updating the firmware using an SD card but it keeps flashing between red and green for over an hour before I give up.

Hi, we're sorry to know about the situation with your Phantom 3 Pro. For a friendly reminder, DJI doesn't recommend our customers to fix the drone by their end due to warranty avoidance. It's recommended to send the unit in our facility for further evaluation and for your to possibly use the warranty but that would depend on the outcome of the damage assessment and the warranty period of your unit. If the unit is no longer part of the warranty period, we have recommended service centers that you could consider to have them fix the drone for your with repair charge. However, this would still depend on our customer's preferences. Please see the link below for our recommended service centers. Thank you for understanding.

https://www.dji.com/service/repair/centers