TI Programmer - Red LED - Key bounce

[Marcel Samek]

Well, I opened it up and the sponge foam sheet between the buttons and keyboard mechanism was completely disintegrated. Just sticky gray dust.

I cleaned it all out with some compressed air. I searched in my garage for some suitable replacement material but could not find anything. Just as an experiment I cut a rectangle of thick felt cloth (about 1.5mm) that I had laying around and put that in there before reassembling the calculator.

It is a thousand times better than before. I still get an occasional key bounce but it is quite usable (at least for now). I'll keep my eye out for an appropriate foam on the assumption that it will work better than the felt.