Was Re: high idle Is: Contact Cleaners

[MSV96 <MSV96@aol.com>]

In a message dated 12/23/97 Sandy Duffy <sandyduffy@home.com> writes:

<<My friend is in the (very expensive) high end electronics repair business.
He fixes $10,000 amplifiers, and $5,000 CD players. Anyway he told me that
nine times out of ten when a customer has sprayed most of the easily available
(Radio Shack etc) contact cleaners into his unit, he is in for a very
expensive repair.>>

I am a cunsumer electronic technician by trade, have been for 20 years
now...this statement mostly applies in my experience to WD-40, not contact
cleaners. The biggest problem with contact cleaners is that some types eat
certain plastics used in switches. While some of the new "cfc free" types may
have some content that can become conductive when it blends with contaminants
present on the area treated I have yet to see that as a service issue.

<<Most of the time spend on aforementioned repair is removing the contact
"cleaner" which has left conductive residue on the circuit boards and
generally "gummed up the works".>>

Again, never seen that from a contact cleaner...and really how long does it
take to clean a pcb???  I see problems from sand all the time (fastest way to
ruin a video camera tape transport or CD player), and from WD-40 ("it squeeked
so I thought it would help"), but have yet to see any customer induced
failures from use of contact cleaners...

<<Reclean all those connections with isopropyl alcohol or trichlorethylene and
the problem might just disappear.>>

Isopropyl alchohol is notorious for leaving the residue you speak of on pcb's
so it would not be a good choice of cleaner. 

With regards to the connectors in our cars (which is what this should be all
about after all) use of a good quality contact cleaner/protectant in the first
place is key. Products such as Stabilant and those from Caig labs have been
touted time and time again here on this list. I have yet to have a repair come
back to me where I have used Caig De-Oxit on switches, controls, and
contacts...this in a marine air climate where these problems are very common.
I swear by the stuff...have for years. Use of a small piece of "scotch-brite"
pad helps on things like corroded ring lugs, etc. too. The thing to be most
careful of is damage to plastic connector housings from chemical attack from
the propellants and contants of contact cleaners you are not sure of.

Hope this clarifies things a bit...Happy New Years all!

Mike Veglia
87 5kcstq