There is no one problem that causes a gimbal problem. You might have a damaged gimbal main circuit board. You might also have damaged bearings or damaged sensors in the yaw motor on the very top of the gimbal. It could be the ribbon cable, although you said in another thread you replaced it.
With the pitch (tilt) problem, you might have damage to the pitch motor or the pitch circuit board. It could also just be the main circuit board or, again, the ribbon cable. It could also possibly be a damaged camera circuit board, although not likely.
The only way to fix it is to send it to someone for repair, or get a working gimbal and swap motors and boards with your gimbal until you find the bad part.