[sdiy] Korg MonoPoly problems

[Bob Weigel]

Tony,
     These movements are fairly notorious for developing a 'glazed' 
surface on the 'conductive rubber' material inside the little cups.  Did 
you also switch the rubber cups from the poly 61?  There are some that 
will require different lengths as I recall.  But anyway to recondition 
them, (we've talked about this before...) a friend of mine who has a lot 
of experience on this sort of thing recommended acetone.  I've done it a 
few times and can observe NO ill effects on the materials involved.   
BUT..the problem seems to be on both these and some other contacts like 
Roland JX10 etc., are that they conductive material gradually wears away 
but...the rubber does not.  This is some kind of 'slurry' in production 
of rubber and conductive material.   Would love to see how they do it 
some day...
    But anyway the acetone possibly helps degrade just the surface of 
the rubber, but obviously has NO reaction with the conductive fraction 
and helps to re-level the playing field..so to speak.  I use a swab and 
just rub them down with it real good and it seems to help.  Often after 
that you need to sit there with the key off and rub the contact against 
the metal in a circular pattern until it responds instantly when you 
touch the surfaces.  Have fun, -Bob

Tony Scharf wrote:

>
> hi everyone.
>
>
> Michael Zacherl suggested I send a post out here about problems I am 
> experiencing with a Korg MonoPoly which I have been trying to restore 
> to some better level of function..
>
> When I got it, she was pretty baddly banged up, particularly the 
> keyboard.  the metal case was in good condition, however, and all the 
> knobs/switches work perfect ( a few are noisy, but I expect that on an 
> instrument this age).  the big problem is the keyboard.  Most of the 
> keys were broken, and had magic marker (!!!) on them.  I found a dead 
> Korg Poly 61 that I scavanged for a new set of keys, and now 
> everything looks fine cosmeticaly.  After that work, only two keys 
> work, and of those one of them doesnt seem to 'gate' properly..
>
> I really want to get this beastie restored.  It has sentimental value, 
> and having gotten the mangled husk for little under $100, it would be 
> a great bargin if it worked again.
>
> Thanks,
> tony
>
>