I have DJI Phantom 2 of 2 Axis Gimbal founded in the pictures you can see that cable connection, it should be correct. In the vertical plane during the flight gimbal gets seizures, which can be seen in the video posted.
Another problem is the reaction on the levers gimbal movements in the vertical plane (the camera is pointing straight ahead and performs gentle movement upwards instead of down).
Hello, try "invert" PITCH axis in Motor configuration tab. If in your shots its real balance of your gimbal, you need rebalance PITCH and ROLL axis before tune PIDs.