ROBERT SAYRE wrote in a message to ROY J. TELLASON:

RJT> This is a *real* important point,  when it comes to contact
RJT> cleaners.  The are basically two kinds out there,  those that 
RJT> leave a residue ("lubrication",  etc.) and those that don't.  I've 
RJT> always tended to favor those that don't.

RS>  I used to be the same way - until I tried Caig chemicals. They 
RS> have some excellent products. I haven't found any others that work 
RS> as well as the Caig products.

What are these products called,  if anything besides that?  I've heard of
some specialty stuff out there that's supposed to be pretty good,  but it
wasn't commonly available and it was more expensive than the usual stuff.

RS>  They even tell you, and it's true, that the less of their product 
RS> you use, the better the outcome!

Hmm.

I *do* use stuff that leaves a residue sometimes,  like when cleaning a
noisy pot doesn't do the trick by itself.  There are a few things out there
that are similar,  RCA called theirs "Big Red" (though it came in
a smaller can),  somebody else calls it "Blue Stuff",  and I'm
sure there are others.  The key is that there's a fine abrasive in the
spray,  jeweler's rouge or something similar,  that "polishes"
the contacts.  This is good for some applications,  terrible for others...

TW> The Chips had a tendenacy to work their way out of the sockets 
TW> anyhow with the Heatup/CoolDown cycles. In fact Reseating All chips 
TW> was part of the Quarterly PM routine.

MR> I noticed some brands of sockets were better with chip creep than 
MR> others. Many early cheap XT clones for example always needed the 
MR> dram pushed down every few months as their chips kept climbing out
MR> of their sockets relentlessly.

RJT> I'd guess that depends on the design of the contact _and_ on what
RJT> metals being used,  both in the chip legs and in the socket 
RJT> material...

RS>  It also depends upon the orientation of the chips, the "bend" of 
RS> the legs, and the impacts that the piece is subjected to.

Sure.

RS>  By using a fiberglass brush and always brushing across the width 
RS> of the legs, not the length of the legs, I tend to cut small lines
RS> across the legs (somewhat like a file) that help to bite into the 
RS> sockets. This works on some connectors as well.

What connectors?

RS>  Sometimes, I use a very fine sand paper on larger connectors and 
RS> get slightly better results. This has cured a few units that were
RS> "tough dogs" for someone else. 

Though I've heard much about chip creep I can't say I've encountered it
much lately...

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