P4 camera won't initialize. From down all the way to center to limp.

Help! I just got a p4 with obviously had a crash. It's got limp gimbal but camera works fine. I opened up the bird and reset ribbon cables and the gimbal moved weakly but it did show some signs of life.
I bought a full gimbal/camera and swapped boards one by one. Now the camera moves to the center then face down 2-3 times and then limp. But it I manually move the camera I feel resistance so that motor must be getting some sort of signal. I'm sure there's a way to calibrate the gimbal but I don't know how. So help, guide and walk me through this please someone must've had this same problem.