I confirmed the bad one by removing the piggyback and the
failure returned. Now I need to desolder the bad one
without ruining the board. I may just cut the leads off
close to the bad chip, and solder the replacement to the
stumps. (Normally I remove the legs and install a
machine-pin DIP socket). Or just solder the piggyback and
leave it there... thoughts?
Cut the leads close to the body. Apply a soldering iron to
each lead, and pull the lead out with tweezers,
simultaneously heating and pulling. This is very gentle to
the board, just doing one at a time. Then, you can vacuum
out the holes and install a new chip or socket.
I've done this many times, and never wrecked a board.
Jon
