More and more users are moving to notebook computers for their computing needs. By nature a notebook computer is a more delicate device compared to a desktop unit. The shell of a notebook is usually made of plastic. Many have some metal in the frames but that metal is usually anchored in plastic. We all have experience with plastic, great stuff but it can break due to wear, shock or stress.
    One thing that we often see are notebooks with damaged hinges. The hinge assembly is one of the weak points on a notebook. It is also the conduit for the wires leading from the main circuit board to the screen. Since most people favor one hand or the other, it is common for users to reach over and close the notebook by grasping one corner and closing the lid. Over time this puts more stress on one hinge than the other. My recommendation is to train yourself to either grasp the lid in the middle with one hand or better yet, use two hands to close the lid by grasping both corners.