modified: Saturday 5 March 2016
Repair: busted laptop hinge mounting point
Even though this page will be short I'm putting up this repair because I think it's interesting reference material. I might start putting up all of the little repairs I do around the place, even if they just end up being picture.
A friend came to me with their laptop for repair. A screen hinge had detached itself from the body of the laptop. Whenever you opened or closed the laptop the plastic body now flexed considerably in ways it should not.
For those not familiar with laptop hinges: they're friction hinges. In order to keep the lid of the laptop in one position they are designed to be very difficult to rotate.
Ordinary users use the whole laptop lid as a lever so the friction is not a problem, but when the hinge unscrews itself then the relatively small hinge acts as a small lever inside the laptop's case, causing all manner of fun and destruction when people open and close the lid.
Problem and repair
This is the mounting point on the laptop body for the perfectly fine left hinge:
Three screws are inserted from above, through the hinge and into the brass inserts. These inserts are (supposed to be) strongly held into the plastic body. The fourth hole is for a screw that gets installed from underneath the laptop.
This is the dodgy right hinge mounting point:
Nothing missing here! Move along!
When I recieved the laptop one insert was already gone and the screws kept popping out of the others. I tried pop-riveting the hinge back into place, but this cracked out the remaining inserts.
In the end I filled the area with epoxy and installed over-size screws:
I left the laptop lid chocked open with some clamps to set overnight. The screws do not bite into the plastic body themselves but instead interface with the epoxy.
Now the right hinge seems to be strong and solid, however the only way to tell its true strength is to break it again.
These hinges have a remarkably small mounting footprint into only the tiniest amounts of plastic case. I'd say that these hinge mounting points are designed to fail.