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Subject: Re: [AN1x] an1x keyboard

From: Bruce Wahler <bruce@...>
Date: 2002-12-09

Hi Ed,

I had a major workstation crash on Wednesday, and I just got to this ...

>> Hasn´t anybody got any idea how to fix this?
>> Very irritating.
>> Anybody done synth maintenance - this is hardly an1x specific stuff.
>
>Bruce... do you want to handle this one? ;-)
>
>(Bruce Wahler, a member of this list, has done much more work on synths than
>me.)
>
>But I'll tell you what I know anyway.
>It's hard. Really hard to fix keyboard mechanisms. They're hard to get to
>inside the unit, therefore you usually have to pull out the whole key
>assembly sub-chassis. Then the method each manufacturer uses to detect the
>key press differs... but usually it's via membrane switches - the same kind
>of thing as on your cell phone. Not very sturdy, and not easy to repair
>once the membrane or rubber or whatever gets bad.
>
>That's the bad part. The good part is that if the membrane stuff is still
>good then the problem is likely that the pressure pads need cleaning. But
>that's still bad because it usually involves removing each key seperately to
>be able to get to the part that needs cleaning.

That's a pretty good synopsis of what goes on inside the keyboard of most electronic instruments. There are four things that can happen:

1) The membrane switches can wear out (not very common).

2) The little plastic "strikers" (my term) on the bottoms of the keys that press the switches can wear down a bit. The mechanical tolerances are pretty tight, so that one of them hits before the other, allowing the velocity to be clocked. The solution is usually to replace the key; sometimes you can swap it with another one, and everything starts working again.

3) Dirt, fuzz, etc. can clog up the striker/switch interface. A little TLC can work wonders.

4) The connectors can loosen up, which can appear as many other issues. Re-seating the connectors often clears this up.


Regards,

-BW

--
Bruce Wahler
Design Consultant
Ashby Solutions™ http://consult.ashbysolutions.com
978.386.7389 voice/fax
bruce@...