Ursprünglicher Beitrag von: cityzen ,
Assuming you didn't physically damage anything, then the most likely problem is that one of the contacts on the plastic sheet is not making proper contact with the connector on circuit board that contains the IC. Now, there are many ways that keyboards can be constructed, but typically there's a connector where the plastic sheet plugs into. Make sure that it's clamped down on to the plastic appropriately. In some models I've seen a little piece of foam that's sandwiched over the connector; make sure that's in place if it's there. If you're 100% sure that the connector is fine, then it's possible that the plastic circuit has a break in it. This can be repaired with a conductive ink pen or brush, assuming you find the break. You should be able to touch different points with multimeter probes to find the break (set the meter to beep when the probes are touched together).