White stuff on RAM adapter board

[Salduchi]

What is the white stuff on the board on this RAM adapter? Are these leaking capacitors? I had bought this FDS brand new and the wire that connects from the RAM adapter to the FDS was very sticky so I assumed it had been stored in a hot and humid place for the last 40 years. I couldn't resist so I opened it up to find this white stuff that seems to have leaked around those round yellow things. What is this stuff?

[P]

Those are ceramic capacitors, they shouldn't be able to leak as they don't contain any electrolyte. Only that blue cylinder-shaped component is an electrolytic capacitor.

It's probably just flux or some other residue. I don't think it causes much of any harm, but if you want you could try cleaning it off using isopropyl alcohol.

I heard flux can become electrically conductive so it should normally be cleaned off after soldering, but if this board had that problem it would have been noticed ages ago.

[Skawo]

Pretty sure that's actually mold.