On 25/06/2017 11:46, Rob Jarratt via cctalk wrote:
I have done a bit more tracing of components and have come across a
possibly anomaly. The signal that won't go low enough goes to the
input (pin 2) of a 74LS125 buffer.
OK, for SOIC parts, here's my technique. (I've had to
replace quite a few of them.) First, use solder wick to
remove solder from one side of the chip. Then, use an
X-acto knife under a pin, and while heating the solder pad,
lever the knife to lift each pin outward and up, free from
the solder. Work your way down one side of the chip until
all leads are free of solder. Now, take the X-acto blade
and score all the other leads right near the plastic body.
Just a couple swipes of the blade is enough. Now, tilt the
body up, press down, and repeat a couple times and the body
will break off of the leads.
Now, remove remaining leads by just sweeping them off the
board, and clean up the pads with solder wick.
Takes maybe 2 minutes, and almost never damages the board.
Jon
