On 1/14/2016 3:01 PM, Gareth Magennis wrote:
Hi,

I have a very old synthesiser where the top panel rubber contact
switches no longer work, because the owner has removed the contact strips.

This is the synth:
http://www.vintagesynth.com/sci/stk.php


The contact rubbers are pretty much 10cm x 10cm x 10cm cubes, but they
have a rather large contact footprint.
The corresponding PCB contact gap between the two lands that need to be
bridged is also rather large.
http://tinypic.com/r/14xdmo3/9



So, I am looking into the possibility of replacing the missing buttons
by cannibalising a somewhat more contemporary keypad that has extra
large contacts.

Here's a typical example I found at Farnell. It might be possible to
cut it up and glue it to the keyboard and make things work, if the
contacts are large enough.
http://uk.farnell.com/storm-interfac...rey/dp/9810064




Anyone any such experience here?

I know it's a long shot.



Cheers,


Gareth.


I'm having a hard time reconciling your text with your picture.
Looks more like 1cm cubes?
And the contact is the circular spot on the bottom of the key?
Rather large???
What part got removed by the customer?

I've had some success with very thin tinfoil glued to the bottom
of the conductive pad on the key.
But, I've not worried about longevity of the fix.
Not sure that would be a good thing for a paid repair for a customer.

I did try conductive silver paint, but that flaked off rather quickly.

Also need to clean the pads on the board well, without scraping off
the black conductor.

Another thing I thought about trying was a piece of "zebra strip"
used to connect calculator boards to their display.
Lay it sideways and properly oriented, because you need a long
conductive path to connect the pads
on the board.