Texas TI-58: Repairing the keyboard bounce and miss to register keystrokes

[Thomas Radtke]

(12-06-2014 06:52 PM)jebem Wrote:  After reading so much reports from others here and there, I have noted that some people can fix some of these keyboard issues by just manipulating the original foam that sits between the plastic keys and the domes.
This makes sense to me, as the foam makes some pressure to the domes forcing them to make a better contact with the keyboard frame wires.
A thicker foam should give better results as well. I did it on one TI-57 some time ago with some success.

I was one of those writing about it. Actually, the foam in my 59 had dissolved nearly completely, so I removed what was left and cleaned the PCB. Unil today, I operate it w/o the foam and it doesn't show any bouncing or missing keystrokes.

OTOH, the same procedure unfortunately failed on another TI (a car computer sold exclusively in Germany).

Anyway, the message would be that this piece of foam isn't required.