Hi, I've bought a crashed P3s with 1 damaged motor and a torn gimbal flat ribbon cable, the roll motor had also detached from the roll arm. I've taken the gimbal/camera apart and fitted a new cable, I've also pushed the roll motor back together (assuming you can do that) and aligned the flat of the roll motor shaft with the flat horizontal line of the camera.
The problem is, when I turn P3s and controller on, the gimbal and camera are dead apart from a bit of noise coming from the yaw motor and it getting warm up by the yaw motor, also the gimbal red light just keeps flashing red.
So the Gimbal is dead and doesn't go through its self calibration on start up, it's just totally dead. Any ideas much appreciated.

I am sorry to know what happened to your DJI Phantom 3 Standard. Since the DJI Phantom 3 Standard crashed before the best thing you need to do is to send the Drone in for further assessment and repair. I will be posting the DJI repair request link ( www.dji.com/support ) for you to create a ticket for your Drone.