Well i can see when trying to push the servo wish makes the motor of the servo turn, the 3D printers screen starts to flash,
The motor is quiet weak,
When i turn the printer off, and i put the arm somewhere else from its home position, the 3d printer sometimes doesnt have enough eletricity and will reboot, This is a psu of 550 watts i believe.

It still works when i give it a gentle push,
My best guess is that one of the plastic gears is broken.