On my Jumper EZBook 3 Pro the black plastic frame on the main body side (not screen side) of the case broke because the hinge on that side became too hard to open. The plastic broke and the brass ferrules were no longer held in the plastic. Thus the hinge on that side was not held down to anything.
I used JB Weld 2-part epoxy, supposed to be good for metal, plastic, and metal-to-plastic bonding, to repair the plastic part. I pressed the ferrules into the glued plastic before the glue had set. I completely removed the hinge and took it apart and sanded it down so that it opened easier. However, it still must have some resistance in order to hold the screen up. When the glue had set (>24 hrs) I replaced the hinge.
For these computers it is important to use a hand on both sides to open them, so one hinge or the other is not too stressed. Or, open in the middle. And do not handle the computer by the screen. The plastic in the frame in the body and on the screen side is fairly fragile.
