BBC Master keyboard

From: <(>
Date: Thu Jan 24 16:28:07 2002

In a message dated 24/01/02, writes:

> Whether you need to unsolder all the keyswitches depends on the keyboard --
> there were 4 types, but only one -- fortunately the least common type --
> needs much work. The best, and original, was the type using Futaba
> keyswitches, which have a white body. These are easy to remove, one at a
> time (desolder the connections, then release the clips which hold the
> keyswitch in the frame). I've seen a couple of pictures on the web showing
> the different types but I can't seem to find one right now :-(
> The normal way to fix faulty ones was to replace them. You can still
> sometimes find switches available from people who've dismantled machines.
> If not, I'd try removing the faulty keyswitches and cleaning them by
> swishing them in a small bowl of iso-propyl alcohol, or squirting IPA
> followed by switch cleaner through them. Finish with a good-quality
> low-residue switch cleaner. These are generally based on IPA with small
> amounts of very light oil (not usually silicone, as it creeps too much and
> gets into everything). Do not use anything like WD40!

>Pete Peter Turnbull
> Network Manager
> University of York

Great, thanks for the advice Pete. Did a quick search with Goolge and found
a few tips on BBC keyboard repair. It seems I have a type I keyboard with
Futaba keyswitches fitted. They come out of the frame one at a time.

After a bit of fiddling I discovered that the keyswitch body is held together
by a small plastic clip and two screws. The terminal pins are the screws
and can be removed by gently rotating with a pair of pliers.

Terminal pins are silver plated and show signs of tarnishing on the faulty
keyswitches. The contact leaf springs appear to be OK. A mild abrasive
and some IPA should do the trick :-)

Just wish I'd kept that Cherry keyboard form years ago with the Hall effect

Received on Thu Jan 24 2002 - 16:28:07 GMT

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