[sdiy] Repairing Key Contacts (OB-8)

[ChristianH]

Hi Tony,

so you found reed switches to be useful indeed? 

For quite some time I've been thinking about everything that might be
remotely suitable as a replacement:
- fixing the rubber contacts in some way (take the risk of destroying
    them completely, e.g. when using harmful solvents)
- creating optical contacs (bad memories, I tried that 20 years ago for
    my Elektor Formant), 
- hall sensors (supply current adds up for 61 sensors, and depending on
    the sensor, you may need something to simulate switches from pulses),
- reed switches, 
- and finally home brew J wires (should be preferably gold plated, but at
    least you can clean em with solvents)

But I still haven't started practical experiments.

Strange thing is - although my OB's keyboard has become pretty crappy, I
have a Polysix that feels like a completely different kind of keyboard,
but it's the same assembly in there. So there _are_ rubber contacts that
are still working as designed. But then, maybe leaking battery acid is
what those rubber contacts really need to stay healthy... ;-)

I wouldn't mind if it gets pricey, something like $200 or more is
definitely worth investing for a durable solution (well, maybe not quite
for a Polysix, but at least for an OB8 or Memorymoog).

cu 
Christian


On Fri, 20 Jul 2001 13:02:31 -0400 (EDT) Tony Clark wrote:

> > I am amazed that the repair kit was not able to fix this problem. It 
> > would seem to me that there is plenty of conductive material there now 
> > to complete the circuit. 
> 
>    I have had mixed results cleaning certain j-wire keyboards.  Some, 
> like my Pro-One and PPG, just refuse to stay cleaned for any lenght of 
> time.
>    This is why I went through the trouble of "Polyfusion-izing" my 
> Pro-One.  Since I couldn't keep the contacts free of dust and oxidation 
> for any given length of time, I replaced them with magnetic reed switches 
> and now I have no more troubles!
>    I _did_ make sure to leave the original wires in place should I have 
> decided that I didn't like it and want to remove it.  :)  It's also a 
> very tricky process to get right, so I don't really recommend it unless 
> you 1) really love that keyboard and 2) aren't going to sell it to anyone 
> else.  :)
> 
>    Tony