"Mossy green" can be a bit concerning as is often a sign that the offending liquid may have had some corrosive content.
Corrosive stuff is usually highly conductive and can act like a
spreading short-circuit if the device happens to be powered up at the
time of ingress so who knows what kind of electrical damage is likely to
result.
Close inspection with a good magnifier - looking for signs of
the solder mask lifting and flaking off. A corrosive substance on a PC
board attacks exposed metals and slowly migrates under the solder mask,
eating tracks as it goes. Also can eat the (usually Tin) coating on IC
pins and migrate into the IC package damaging it. PCB plate thrus and
tracks underneath flat components like IC's are particularly vulnerable
to corrosion damage as well.
It would be
interesting to see what lies under that 20 pin chip, firstly inspection
of the underside of the board, looking for signs of Mossy Green around
plate thrus and tracks.
Good luck with it. I've found that it's better for one's own sanity to toss it if there is any sign of corrosion.
Cheers