apple Lisa2. Keypads

On 12/23/2010 03:06 PM, Terry Stewart wrote: Wise ass answer to why anything deteriorates would be entropy. :-) No idea. I would guess, and this is just a guess, that since these materials are a depositing of metal particles on top of plastic, that the bonds wear out over time. Whether that's because of oxidation, or mechanic wear and tear. In this case since almost all of the keys are worn out like that, I would say it's unlikely to be mechanical wear and tear. This is because most people don't use every key on the keyboard with the same frequency. You'd find some keys like the "CLEAR" key on the numpad would be almost never used. So if most of them are totally worn out in that way, it's got to be some chemical process. So that's the beauty of using taped over aluminum foil. It last a hell of a lot longer than mylar. It's unlikely that 10 years from now it would disintegrate like the mylar did. The hardest part is cutting the rounds to be all the same shape/size. Not too hard if you find a plastic tube of the same diameter as the original mylar rounds and use an Xacto-knife (aka- small sharp razor on a pen.) Make it yourself, less trouble. And while you're at it, find some foam. I'd replace all foam and mylar in all of the keys in the keyboard. This way you won't have to redo it again for a long time. I'm not exactly sure where you'd be able to get new keypads from anyway. Maybe there's a place that makes these still, I don't know. But once you make one or two replacement keys and verify that they work, repeating the process is very easy. And better yet, if you replace all of the foam now, you won't have some keys that feel mushy and others that feel stiff. Instead, they'll all have the same tactile feel. The keyboard will feel like a new keyboard. Well worth the 1-2 hours of trouble, IMHO. But, just out of curiosity, where exactly would you order keypads from?