Cleaning those rubber thingies

[Martin Czech]

> Has anyone come up with *the* solution to clean those rubber pads under a 
> synth-keyboard? My Roland SH-101 keeps getting dirty key contacts. And 
> since I have a TV remote controller that has the same kind of rubber contacts 
> and suffers from the same problem, it would be nice if someone had found a 
> way to keep these darn things clean.
> 
> Jeroen
>
This seems to be the Roland Desease. My D70 also suffers from
malfunctioning contacts, midi messages come out, but velocity is 0.
The system is as follows: grey rubber cussions contain black resistive
rubber contacts, the cussions are attached to a pcb (clamped, not
glued). A pressed key squeezes the cussion and the first contact
closes, then the second (velocity). I asked the Roland official at the
Frankfurt music fair, they know the problem. First: little particles
can stick to the rubber surface and interrupt contact. Try to get rid
of them with air pistol (also compressed canned air). Be shure to use
clean air, many workshops have dirty oil aerosol air, this will make
things worse. If this doesn't help, try alcohol or mild "tuner" cleaner
and q-tips. Replacing the contact set won't help, because the whole
contact thing works like a vacuum pump. It sucks (yes, you allready
know ;->) all kind of dust into the mechanism during operation. Remedy:
try to seal the ventilation openings with some kind of
non-particle-emitting foam or tissue. Try to glue the grey contact
rubber to the pcb, this interface is where the dust gets mostly in. But
the air must still be able to flow.  Otherwise key action will be
strange (farthzz, farthzzz , hae , hae).

A unhappy D70 user.

m.c.