Re: restoring circuit boards

["Mark Cummings" <NOTfigjams@primus.com.au>]

> Anyway, that's a really cool web page!!! I posed the question on cleaning
&
> restoring logic boards awhile back on this newsgroup. Your procedure is
> quite interesting, and it's almost exactly what I originally had in mind.
> It's also different from the ones mentioned on the replies to my request.
> Some of the other recommendations included dipping the logic board into a
> cleaning solvent and using a vibration process, or even dipping the logic
> board into soap & water, then let it drip-dry for a couple of days.

dipping into a cleaning solvent like isopropyl alcohol (which I think is the
same or similar to rubbing alcohol ?) is fine if you can find enough of it.
you'd need about a litre though which is a bit of a waste and costly. using
a brush and a dispenser you'd be using less than 50mL I guess.

for professional cleaning the first step is to clean with a brush and
isopropyl first to remove most of the built up flux, then submerge in
isopropyl in an ultrasonic cleaner overnight. having a large ultrasonic
cleaner that could fit a motherboard in is not normally that easy to get
hold of for your average hobbyist, and the results are not that much better
to an untrained eye.

definately don't leave it drip dry, what happens is that the contaminants in
the water will dry onto the contacts inside switches etc. possibly starting
corrosion. also you will see watermarks all over the place. after blowing it
dry you can see instant success and if it's not 100% you can have another go
straight away. besides that you can re-assemble it straight away and switch
it back on.

Mark