Try to contact the manufacturer of the product containing this rubber
keypad for a new keypad. With some luck you will get it for almost nothing.

Some times ago I've tried to repair a keypad on an older Fax machine.
The amount of work (time) for this task exceeded the cost of a new one
(Fax).
Of course if somebody would pay me for the time I spent on this.

There are a few methods for repairing.

- thin self adhesive copper foil could do it.
- carbon paint for silkscreen printing could do it.
- gold foil for repairing letters on thumbstones could do it.
- a conductive silver spray could do it.

Any other sugestions ?

Regards, Andrej

----------
> From: Lee Jones <lee@FRUMBLE.CLAREMONT.EDU>
> To: PICLIST@MITVMA.MIT.EDU
> Subject: [OT] conductive coating for rubber membrane keypad
> Date: 25. november 1999 10:20
>
> Hi all,
>
> I'm looking for a small quantity of conductive coating to
> repair a rubber membrane keypad.  I got some oil between
> the rubber membrane and the PC board.  Alcohol cleaned off
> the oil just fine.  But my overly vigorous scrubbing with
> a Q-tip also removed the conductive coating on a few keys.
>
> This is the style of keypad where there are interlaced
> fingers on the printed circuit board.  Underside of each
> key is a dome of rubber with a raised spot in the center.
> The raised spot is coated with a conductive substance.
> When the key is pressed, the conductive coating closes
> the circuit by "shorting" the fingers together.
>
> Anybody know if this conductive coating is available for
> repair work?  If so, a vendor and part number would be
> nice.  Or is this material the exclusive province of the
> people who make rubber membrane keypads?
>
> Thanks in advance.
>                                                 Lee Jones