[sdiy] how to fix JX-8P keys?

[Bob Weigel]

These are the rubber cup switch arrangements.  Sometimes they get actual 
dust/dirt under them.  I just cleaned up an old AX73 of the same 
technology last night.  WOrked great after getting all the crumbs out 
save one note that I had to pull the key off from and 'massage' it 
around with a blunt end probe.  (You can actually kind of fine sand the 
surface some without even pulling the contact strips out)

Other times (eg. my memorymoog) I've seen contacts be very persistently 
foul. I'd like to develop something that will really allow people to 
repair those contacts.  Nickel print won't stick to silicon at all.  
Most other things won't either of course.   In the meantime

1) Sometimes acetone will eat a little of the surface rubber and leave 
the conductive impregnated material.   Treat it, scale the surface with 
an exacto etc. and sometimes it's good. Measure with probes.  You should 
have a conductivity of 500 ohms or less when you press them side by side 
on the surface of that stuff.  If it's 1000 ohms they are going to be 
totally flaky usually.  700 might work ok in most apps I've seen.

2) Light abrasive can sometimes bring them back

3) Sometimes the contact just seem to have no conductive material left 
in it! :-)  I have ones from a Mono/poly I did in my studio that simply 
can't be gotten back..like one or two per strip!  Bad lot of them?  I 
think so.

That's my research on the matter.  I've even though of...drilling a very 
small hole..#70 maybe...in the center of a contact.  Then put nickel 
print on there :-).  I'll bet it would work.  -Bob

Dino Leone wrote:

> Hi all,
>
> I have a Roland JX-8P with a couple of flaky keys - sometimes they  
> work, sometimes they don't. If you hit them hard they always work.
> Before taking the thing apart, I wanted to ask if anybody has  
> suggestions on how to clean the keyboard contacts?
> Many thanks in advance,
> Dino
>
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