If you do find leakage it can be cleaned off, either by using some kind of cleaning alcohol like isopropanol or brake cleaner along with cotton buds; or the more drastic approach of washing the main board, (with SIMMs and battery removed), in a bowl of soapy water or a dishwasher. If using the latter methods, give the board a couple of days to dry out before powering on!

My first SE/30 had this issue but cleaning off the residue with alcohol and replacing the PRAM battery did the trick, it has worked fine since (although with low speaker volume).