I have my friends phantom 3 advanced here with gimbal issues, for starters this quad was involved in a crash that broke gimbal parts and ripped the ribbon.
I decided to go and fix it for him, I rebuilt the gimbal and camera put new hardware and ribbon cable in and plugged it all up. Now I dont have gimbal power or video from the camera and no startup dance/calibration.

DJIGO app definatly knows somethings there because when I move the camera the tilt is registering on the app. No signal though and the app says gimbal status is good. Unfortunatly I get "gimbal tilt" and "Camera needs update" errors that comeup. Putting an sd card with any P3A .bins yields d-d-d which tells me that the firmware is either corrupt and/or not updating properly..I also get no blinking lights on the gimbal. The app shows sd card having 0 space available. On top of that the bird now shows up as a P3P in the start screen. Ive tried 2 other P3A gimbal boards and 2 other cameras, 2 different ribbons and replaced all cables in the bird and I still have no power, control or vision from the gimbal and camera.

If anyone can help with this Id be dang greatful.

Sorry for the crash,Tychon.
Probably you didn't install it properly.
I'd suggest you to send it in for further evaluation.