Originally Posted by ds11
While cleaning rosin flux off circuit boards is good, what's the harm in leaving it on cable joints?
It is not necessary to clean rosin off circuit boards unless working with UHF and microwave circuits. It does make it look pretty and you can see imperfections or cold solder joints easier but it has no effect on the electronics. I have been making boards and soldering since 1965 and never had issues with rosin.