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Re: Cleaning old Apple II cards?
atfphotography@gmail.com wrote:
Hello,
My question of the week.. HAH!
So I went and looked about on Google and such and found a fellow
giving tutorials on cleaning cards. He was using denatured alcohol
(acetone?), a toothbrush and a dry air can. Toothbrush into the
denatured alcohol, clean the card in a spot and then quickly blow off
the alcohol.
That's *monster* overkill for any dusty card. Just blow it off and
lightly brush and re-blow.
Liquids are almost never needed, and a toothbrush is usually a little
too "stiff", since it can bend bypass caps, for example, which can
result in leads breaking. (My preferred brush is a "draftsman's" brush
used for clearing eraser dust from a drawing.)
Anyone have comments? Several of my cards are pretty dirty with dust
as well as some corrosion caused by a bad battery above some circuits.
Corrosion is another matter, particularly since cleaning may be the
least of your problems.
Cleaning repeatedly with a damp Q-tip will usually remove any soluble
corrosives. Then carefully inspect the area to see if any traces or
components have been damaged. You can repair "open" traces by cleaning
to bare copper (with, say, an "ink" eraser) for about 1/8" on either
side of the break, then carefully tin the copper and solder a thin
solid wire across the break. Damaged components should be replaced
(hopefully you can still decode the markings).
(As we all know now, attaching batteries to a PC board is generally
a bad idea, since battery leakage is more a matter of "when" than "if".)
BTW, some people just put PC boards in the dishwasher (no detergent),
which works fine if all the components on the board are sealed and
you let it get *completely* dry--even under the ICs. The problem is
that the way you *know* that all components are sealed is that the card
still works after this treatment. ;-)
-michael
NadaNet 3.0 for Apple II parallel computing!
Home page: http://home.comcast.net/~mjmahon/
"The wastebasket is our most important design
tool--and it's seriously underused."