Looking for motherboard and wiring info for Lisa 1

From: Bill Dawson <whdawson_at_mlynk.com>
Date: Thu May 25 00:18:11 2000

-> > It appears to me that the motherboard socket that is missing
-> > one pin will need to be replaced. Anybody have any recommendations on
how
-> > to best do this? The motherboard is a four layer board. I have
-> > soldering/desoldering experience, but I've never tackled an item with
this many pins
-> > on a 4 layer board before.
->
-> Assuming the old connector is worthless (or at least worth a lot less
-> than the motherboard), I'd recommend breaking it up and removing it in
-> sections.
->
-> Sometimes you can cut away the plastic _carefully_ (you don't want to
-> damage any tracks on the board). More often, if you heat the pin
-> from the
-> solder side of the board you can pull it out on the component side --
-> right out of the plastic housing (which will melt slightly from
-> the heat).

->
-> Once you've got all the pins out and the housing removed, then melt the
-> solder in each hole with the iron from one side of the board and
-> suck out
-> the solder (with a solder sucker or 'Soldapulit' (IIRC)) from the other.
-> Put the new connector in place and resolder it.
->
-> If you can get a spare pin of the right size you _might_ be able to
-> remove the broken pin only, clean out the solder from the 'back' of the
-> board and put a new pin in place, leaving the rest of the pins (and
-> connector housing) alone. I've done it a couple of times

My thoughts exactly. Of course the broken one can't be grasped and pulled
through if it is broken off flush with the connector, but it may be able to
be heated and pushed through enough to nab. Barring that, I've used a sharp
stainless steel pick the same diameter of the pins to push pins through
enough to get a hold of them on the connector side. Just heat the pad and
the pin (it help to apply a little extra solder), and once the pin is loose
in the hole gently push the pin. Sometimes it also helps to trim the solder
side of the pin flat so the pick won't slide off. Once the broken pin is
out, remove one from another connector by pulling it out. A little heat may
make the job easier if it is stubborn. Then, assuming the pin hole has been
cleaned of solder, push in the replacement pin and resolder it. This is
always much easier, IMHO, than replacing an entire connector for just one
broken pin.

Bill


->
-> -tony
->
Received on Thu May 25 2000 - 00:18:11 BST