I used to skip cleaning flux off old boards until a repair came back

A customer brought back a 1980s stereo amp I fixed six months ago, saying the left channel was cutting out again. I opened it up and found the old flux residue had turned conductive and was causing a short. Now I always use 99% isopropyl and a soft brush on every board, even if it takes an extra ten minutes. Has anyone else had a comeback because of leftover flux?

3 comments

3 Comments

the_luna3mo ago

Wait, flux can do that?

loganhart3mo ago

It seems pretty limited from what I've seen.

riverp3714d ago

Had a 70s marantz receiver come back six months after a recap, flux had bridged two pins on the volume pot. Now I hit every board with a UV light after cleaning just to catch any residue I missed.