10 Sep
2008
10 Sep
'08
8:52 p.m.
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).
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.
I've started taking the chips out one by one and cleaning the legs by
running them over a strip of scotch-brite. This clears off the
corrosion (and some of these are VERY corroded). I've then been (again,
carefully) bending the pins out slightly to allow them all to make good
contact with the socket. I did a row and a half last night, verifying
the continuity of the connections after each chip. It only took an hour
and a half :). At this rate, I'll have all 25 rows done in a couple of
weeks :).
I'd take some pictures to show you what I'm up against, but I lent my
camera out...
Thanks for the suggestions...
Josh
Chuck Guzis wrote:
My take on this:
On 10 Sep 2008 at 21:11, Randy Dawson wrote:
with a screwdriver, (lever off adjacent IC) end
then other end, walk
the ic 3/4 out of the socket and re-insert it. 10 minutes to do the
whole board 25 rows of 13 chips.
I've found that stuff stored for a long time builds up a coating of
dust and gunk (oil, grease?). Better to use a solvent cleaner on the
chips and sockets than shove the crud back into the socket.
I wouldn't use a screwdriver--take some scrap steel or aluminum sheet
metal and use it to make an "L" shape. The length of the horizontal
part of the "L" should be nearly the length of the chip and about
2/3rds the width of the chip between pins; the vertical part should
be long enough for you to use it as a handle. Slip the leg of the L
under the chip and gently rock it from side to side using the
vertical handle until the chip pops out. You're much less likely to
bend the chip pins this way.
Pencil eraser on the gold fingers on the card
edge too, until they are
nice and bright.
If you have to use an eraser, use a gum-rubber one without the "grit"
most pencil erasers have. Better just to wipe the edge connectors
with a contact cleaning solution.
My .02 anyway,
Chuck