"mike"

Clean it WELL with something like Simple Green. Use a toothbrush
and get it out from between chip pins, under chips, inside via holes.
Blow it dry and clean it again.
Then do it twice with high-concentration alcohol, like the 99% stuff
you can get a the drugstore.

** De-natured alcohol " (Methylated Spirits ) works fines to.

As do most PCB cleaner sprays.


Then dry it as hot as you can without breaking the parts.
150F is reasonable.

** 150C is highly unreasonable.

It will destroy electros, melt some plastics and harm some semis.

100C should be the absolute limit.

70C will do the job quickly.


.... Phil