Re: Dead keys on Edirol PCR-50

"Mogens V." <mogensv@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
Gareth Magennis wrote:
<mick.ohrberg@xxxxxxxxx> wrote in message

I have after some inactivity realized that most of the keys on my
Edirol PCR-50 are dead. I'm guessing it's due to the contact pads
oxidizing. I have carefully pried the rubber bellows off of the PCB,
and I assume the reason the two contact points inside the bellows are
at different depths are to capture velocity data.

(Please see for detail pictures)

How would I get my keys back? I have tried alcohol and scrubbing the
contact points (both on the PCB and the bellows), but to no avail. Do
I need to sand the contacts down a bit to get rid of oxidation? The
pattern of live/dead keys does not (to me) support the notion of a bad
line on the PCB.



Its not usually the PCB contacts that go bad, its the contacts on the
rubber strips. You could try cleaning them with alcohol and a cotton
bud, or else you will need to buy some new ones.

I've heard some fixed them using an eraser rubber, probably doing it
gently. No mentioning which kind, i.e. eraser rubber for pensil or ink.

Kind regards,
Mogens V.

I wouldn't use anything at all abrasive on the PCB, there's simply no need
and every chance of wiping out the printed contact. You can't do any better
than degrease it with alcohol. Cleaning the rubber strips with alcohol can
sometimes work, but I never do that anymore because far too many have been
just a temporary fix and have come back in again a few months later. New
contacts are cheap and always solve the problem.

Sometimes the problem is actually due to small pieces of dust, tobacco etc
that finds its way under the rubbers.

Incidentally, you can buy liquid contact repair gunk that you paint on worn
contact strips. Its very expensive and doesn't work at all.