Commodore 64-sx Keyboard getting stuck?

[Bjørn Vermo]

On 11 Jul, 2005, at 21:18, Ethan Dicks wrote:

> On 7/11/05, Dwight K. Elvey <dwight.elvey at amd.com> wrote:
>> If that didn't work, a last resort might
>> be to use some small wire wrap wire and melt a channel
>> into the plastic layer to keep from deforming the stack
>> too much
>
> I've seen the results of attempts at that.  Let me put it this way -
> try it right before you are ready to pitch the whole mess.
>
> there's not enough pressure to make contact between oxidized traces
> printed on mylar and any kind of wire.  The mylar sheeting is thin
> enough that you are more likely to perforate the mylar than "melt a
> channel"  _Perhaps_ some kind of foil overlay might work, but it would
> have to be akin to gold leaf, and you'd need a solder alloy that
> melted below the temp of the plastic to get any sort of joint.  For
> that matter, if you had an uber-low-temp solder (200F?  300F?), you
> might be able to overlay entire traces with WW wire, but not if the
> plastic develops holes.

There is a kind of silver paste used for thick-film circuits which 
might be usable for this type of repair.

-- 
-bv