[Coco] Gold Plating the Tin Card Edge Fingers of Old Coco Paks, MPIs, etc.

[Rogelio Perea]

On Sat, Apr 13 2013, Kip Koon wrote:


> I'm having great difficulty keeping my Coco 3 compatible MPI operational.
> It worked fine yesterday.  I disassembled my Coco 3 setup to test some
> other
> cocos and when I set my Coco 3 setup back up with the Coco 3 MPI later on,
> it was a no go.  The Coco 3 will not boot up, even with no paks plugged
> into
> the MPI.  It'd just the Coco 3 and an empty MPI.  I looked at the card edge
> contacts and they are awful! Yuck!  No wonder it isn't working!  How do I
> revive those card edge fingers plated with tin.  It is possible to have
> them
> gold plated somehow without completely removing everything from the PCB?
> Any ideas would be greatly appreciated.  Thanks in advance.
>

Looked into the gold plating option a while back and did find a company or
two that sell the stuff to gold plate such card edge contacts, it is
applied as one would apply the repair paint to a broken heater trace on a
car back window, did not make a note of the information found as it was
VERY expensive and as it is practically 'painted over' (the gold part of
it) there was not much guarantee about the durability of the finished
contact, for sure not close to what we could get with an electro deposit
process, and that one could also be done but much greater expense - these
things are heavily dependent on the production run at hand, doing onesies
and twosies drives the cost high.

The cheapest way - although a nuisance - has been for a long time the
glorious pencil eraser method. I have upped the cleaning runs by adding
DeoxIT applied with a cotton swab on the card edge contacts once
eraser-wiped, don't like to use the aerosol version as it will spray
everything else that does not need DeoxIT in the cart. The contacts on my
MPI to CoCo last considerably longer cleaned this way.

There was once a company back in the TRS-80 Model I heyday that sold add-on
gold plugs (EAP was the brandname I believe?), now having *that* option
would be the one easy and quick fix to do, you'd just have to live with a
slightly out of its socket interface cart into the CoCo/MPI due to the
extra length added by the plug. On my quest a couple of years back I did
not find ANY vendor that would sell something like this plug. Bummer.


-- RP