Re: Cleaning TM500 module pushbutton switches

Bill Perkins

Looking eBay:

I see about 27 different offerings, what's your recommendation ?


I do not recommend using WD40 anywhere near the TM500 switches.
as I explained earlier, using de-oxit (which is slightly lubricating),
and letting it fall right
to the front plastic shaft solves ALL seizing problems in the switch
assembly, as well as fixing the contacts.
let it drain down to the shaft from the open back, work the mechanism
rapidly at least a dozen times, and
you should have good results. I have also had good success with nu-trol,
used in the same way from the
 open back of the switch.
I have done hundreds of these switches both in the TM500 and 7K /5K
series. I am 100% confident
that the process I described will work IF ANYTHING CAN WORK (in other
words if there's any good
contact surface left in the switch). I strongly advise against anything
like solvents, WD40, oils or
other highly active chemicals, and I have NOT found that disassembly and
manual cleaning works
any better than the process I described, although disassembly can be
useful when the sliding
contact has to be replaced. to be candid, if it's at that point, the
switch itself has to go.
we used a variant of this same switch (the origin of which goes WAY back
to itt-schadow in europe) for many
years in avionics systems as well, but paid to have the contacts gold
plated from E-switch, and had almost no failures over decades of use.
just my $0.02 worth on this topic.
all the best,

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