Old Matrix 6 Keyboard Mechanism info needed

Connie and/or Dave Garfield conidave at pacbell.net
Thu Feb 19 04:07:07 CET 1998

«» «» «» Philip Pilgrim«» «» «» wrote:
> I picked up an Oberheim XK controller keyboard. It is very nice however some of the key contacts seem like some cleaning may help.
> Does anyone know the procedure for doing this? The contacts seem related to those rubber ones in most remote controls for TV...
> <snip!>
> Thanks
> Philip

Hi, Philip!

	Why, it's ME, yer' ol' pal Dave Garfield - owner of your Polysix Chorus
Board (works PURR-fectly, BTW!) and Advice-Monger.  Looking back in my
Vast Hoard of old email, I found this:
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> From:   Mark Pulver[SMTP:mpulver at midiwall.com]
> Sent:   Monday, September 22, 1997 6:34 PM
> To:     Peter Harlan
> Cc:     analogue at hyperreal.org
> Subject: Re: Mono/Poly key question
> >I've read about the injurious effects of some cleaners on rubber.
> >What about just using rubbing alcohol?
> You don't want to use alcohol on rubber for the same reason that you really don't wanna run gasoline with Ethanol in your car... It'll cause the rubber to dry out, crack, and basically disintegrate.
> There are contact cleaners on the market, basically nothing alcohol based. DeOxIt is probably the most common thing around.

> Mark Pulver
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Anyway, I had a couple of funky key contacts in my Mono/Poly when one of
the cats decided it needed a little "decoration", and 'marked' the
keyboard. }:-<  It, too has the stoo-pit rubber bump-y (rubber baby
buggy bumpers, anyone?) switches, and of course, the "kitty juice" had
managed to go under the rubber, onto the board!  I removed the keyboard
PC Board, and found that the rubber thingies were easy to detach from
the board, by using needle nose pliers to compress the rubber fasteners
one at a time.  After rinsing the board with water and scrubbing it with
a toothbrush, I used an ink eraser to scrub the contacts, then acetone
to Thoroughly clean any possible residue (CAREFUL!  Acetone Loves to eat
plastic parts - keep it on the Solder Side!).  Being VERY Careful not to
lose any of the little carbon-y buttons inside the rubber domes (a sink
with a stopper really helps here), I washed the rubber bits with dish
detergent, which shouldn't appreciably shorten the life of the rubber,
dried them Thoroughly with a spotlessly clean towel, and using a cotton
swab and Completely Denatured alcohol, went over the buttons ONLY,
trying not to leave any on the rubber parts.  Making sure that
everything was Bone-dry, I reassembled it in the reverse order.  It took
a while to get the keys not to "stutter", even after the cleaning, but
it eventually calmed down after further playing.  

While it may not be the reccommended way to clean keyboard contacts, and
while there may be some aerosols or other cleaners that can do a better
job, this method Works, and uses readily-available items.

Hope this helps!  Best of luck!

		Yours in "Anti-Stutter" Mode,
		Dave Garfield
		Conidave at pacbell.net

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