From: mwandel@bnr.ca (Markus Wandel)
Subject: Rejuvenating keyboards
Date: 13 Feb 1996 20:00:06 GMT
I just missed a thread on patching up failing keyboards and thought I'd add my own experiences. First of all, I've never seen a rubber contact keyboard that can't be rejuvenated completely unless the rubber membranes are disintegrating. You simply give the PC board a thorough scrub with Windex (ammonia based window cleaner) or similar, and clean all of the little rubber contact buttons the same way (this takes work.) Reassemble and the keyboard should be perfect. The bad keys may take a bit of scrubbing. Don't put all the little screws back in before testing the keyboard since you may have missed keys, or have a bit of cleaning tissue lint stuck to a rubber pad, or whatever.
I have applied this treatment to the keyboards/pads in Commodore PETs, a VIC20, C64s, and numerous telephones. All worked like new afterward. The only one that didn't stay working was a telephone keypad that had been polluted with some sort of sticky fluid, that kept coming out of the corners you can't clean and polluting the contacts again.
It should be unnecessary to swap the rubber parts of the keys around, but in the VIC20 keyboard I just had apart the other day, the grey rubber membrane with the black contact button can be popped out of the bottom of the key assembly. No need to pull the key off at all.
Trivia -- in the (first release) VIC20 that I had apart, the keyboard housing looked similar to that in a PET, and had key holes for a numeric keypad, of which four were used for the function keys and the rest taped over. I'll bet that part was originally for a business-style 8032 keyboard.
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Markus Wandel Ottawa Ont. Canada (613) 592-1225
markus@pinetree.org <-- NOT 'mwandel@bnr.ca' (that's for work only)