On Jan 21, 8:10 am, "StellarTech" wrote:
I assume you are referring to pcb-mounted momentary contact switches. The
best remedy I have found is WD-40. Use the nozzle tube and apply a small
amount right to the small gap where the actuator protrudes from the
housing. Then rapidly & repeatedly push the actuator about 20-30 times.
You may have to apply the '40 more than once. And of course, clean the
PCB afterwards. I assume it's the foaming action of the WD-40 that allows
it to get to the contacts in the switch. At any rate, it usually does the
trick.

Dont do this! Without wishing to start yet another WD40 war, the
damaging effects of WD40 on electronics are well documented. The
manufacturers of WD40 themselves do not advise applying their product to
electronic components.

There are plenty of products designed for the purpose of switch cleaning.

Ron(UK)Wow, I'm surprised to hear this. And I'm not being facetious. I can only
assume that this "war" raged on before I started reading this newsgroup.
As I mentioned in an earlier post, I'm new here, just getting my feet wet.
And my only intention is to pass along what I thought to be good advice.
I would like to hear more about the WD-40 debate (or skirmish), perhaps
you could drop a short new post? I would like to hear more. But I would also
like to clarify my point. I serviced consumer electronics for 27 years
before
I retired due to disabilities (3 years ago), and I can't ever recall having
to
re-service any unit due to the use of WD-40. As I said, use only a small
amount of the product, applied right where it is needed. And cleaning up
afterwards. We're talking about miniature switches, handling only keyscan
pulses from a processor. And I certainly wouldn't expect or recommend
using it where higher power circuits are involved. It's just that I can't
visualize a small amount of WD-40 on the surface of a pcb causing a
problem.

At the risk of (re)starting a WD40 war: WD40 is a blend of waxes and
solvents. It is very good at DISSOLVING numerous kinds of
polymers...such as those used to make flexible keypads, sealing
electrolytic capacitors, moulding complex mechanical parts, adhesives,
etc. WD40 has been found to be capable of dissolving (literally) the
resistor material used in SOME potentiometers (linear and rotary), glue
used to hold complex switches in assembly, and the
conductivity-enhancing black coating on some IR remocon PCBs. It takes
only a fraction of a drop to do any of this.

Given enough time, residue (wax) from a WD40 coating will attract
enough ambient dust to form conductive paths where the designer did not
intend them to be, thus destroying components. WD40 is a good TEMPORARY
solution for squeaking door hinges...temporary because WAX IS NOT A
LUBRICANT. WD40 can do nothing positive for electronic equipment other
than hasten its replacement. IAW: You don't recall re-serviceing
anything because of WD40 because the next failure was probably so
catestrophic that the item went to the dustbin as soon as the smoke
cleared.

Don't misunderstand...I'm a WD40 enthusiast. I have a 1-gallon tin of
the stuff under my work bench for use as a cleaner...because it is the
best I've found for cutting heavy grease, adhesive tape residue, and
rinsing crap out of tiny ball-bearings. Just don't ever think of it as
a "contact cleaner" or "tuner cleaner." It isn't.