12 Sep
2008
12 Sep
'08
12:12 a.m.
Chuck Guzis wrote:
None of the chips in question have gold plated pins, so I can't make
things too much worse there :). I'll get some DeoxIT and see how that
goes.
On 10 Sep 2008 at 20:52, Josh Dersch wrote:
I may just do that. I'm finding more and more of these chips are
leaving pins in the sockets no matter how carefully I extract them. I
have two of these ND-812 machines, one of which is basically good for
parts only (the power supply's been stripped and the front panel looks
like it was left in the sun too long (the toggle switches are actually
melted!) so I have a set of spare chips... I hope I can manage to get
one working machine out of the two.
The aluminum sheet idea is great, except that on
this board there's
really no room to slide it in -- the chips are close enough together
that I can barely get a small flat-blade screwdriver between them to pry
(gently).
You could also try making an extractor that's modeled after forceps--
a short horizontal "L" section on each leg, just long enough to clear
the space between chips. Some of the pins on these old ceramic
packages are very fragile.
And I reseated all the chips the other night
(very carefully). Going
through with a continuity tester on the first couple rows reveals that
about every other chip has at least one pin that's not making good
contact... this is going to be an ordeal :). The sockets themselves are
going to be a problem -- they have gold contacts (I _think_) but the
actual socket doesn't expose any accessible metal surface -- the pins go
through a hole (that's just barely larger than a pin) in the plastic
sheath and beneath that are the contacts. So getting contact cleaner in
there is going to be an interesting problem.
DeoxIT comes in an aerosol form, which should allow for easy
penetration.
The concern here is that with abrasive methods, you're also rubbing
off the gold plating with the corrosion. That could mean some misery
down the road.
None of this may help you if the sockets have degraded
to the point
where the contacts have deteriorated and cannot make good contact
even after cleaning.
I'm thinking that this may be the case. In which case
I'm not sure how
much it'd actually be worth replacing every socket... what a pain. :)
Thanks for the suggestions...
But a chemical cleaner such as DeoxIT is
probably the best way to approach the problem of dirty/corroded
contacts.
Cheers,
Chuck