Restoring a Lisa keyboard and could use a few tips

[Huxley]

Hi all,

The keyboard that came with my 'new' Lisa 2/10 is in semi-functional condition. Most of the keys would respond after a couple firm presses, but it was pretty clear that the foam-and-foil discs inside had degraded. I've just finished the painstaking task of replacing all the discs, and I'm pleased to report that every keypress registers as expected. Whew!

With that part done, I'm left with two remaining issues - I'd be grateful for suggestions on either of these:

Issue 1: unpleasant key action
Specifically, most of the keys feel very 'grindy' when depressed, and not all of them want to immediately rise back into position after being pressed. I suspect that I could perhaps improve this by using some key switch lubricant, but I've never done this before. If anyone has a tip or suggestion on the best way to lubricate the keys on this keyboard, I'd be happy to hear it!

Issue 2: cracked plastic case
At some point in its existence, this keyboard seems to have been dropped on one corner. There's a crack running from one corner along the top case, and I'd really like to prevent it from spreading further. How would you suggest doing this? Perhaps some plastic-safe glue applied from the inside? I don't want to cause any more damage with a clumsy repair attempt here...



Thanks in advance for any guidance on these topics!

Huxley

 

[Juror22]

Drilling a small hole at the end of the crack will stop it from spreading.
If this were mine, I would do two things.
1) Practice the fix on similar material.
2) instead of a drill, I would use hot wire about 2mm in diameter and starting from the inside of the piece at the end of the crack, create a small melted pit that does NOT penetrate the plastic completely. A fine tip soldering iron would work for this as well, but be careful not to apply too much heat. I cannot stress this enough, practice on a non-Lisa piece of plastic first. I've had excellent experience with this method of fix.

 

[ObeyDaleks]

I don't have a Lisa but I assume this keyboard is made of ABS, in which case I would recommend acetone to close that crack. I would apply some with a brush from the inside of the case, then wait a few seconds and press the two sides together. I usually put some tape over the front before pressing firmly to block melted plastic from oozing out the front. If you do it right, it will be permanently welded and should be almost invisible,