While checking a spare Lacuna board for damage, I noticed some wetness
and corrosion in the RAMDAC area. The culprit is an incontinent
electrolytic capacitor (C68):
https://www.ardent-tool.com/76_77/Lacuna_C68_Photo.jpg

It's a 10 uF / 25 V (d = 5 mm, l = ~5 mm) electrolytic cap.

Thankfully, it's the only cap of that type on the entire board. The rest
seem to be ok.

After this discovery, I checked all my other Lacunas, and four out of
four had the same issue (all from Greenock, UK - identified by the 55-
plant code prefix in the unit's S/N).

Check your Lacunas if you want them to survive. The electrolyte will
damage nearby components/traces/vias if left unchecked!

You can snip the sucker off if you don't feel confident about your
soldering skills (left some of the leads left so you can pull them out
later). It's just a bypass cap for the RAMDAC - the video subsystem will
function without it (it may introduce some interference into the video
output, but I have not noticed such side effects, at least not during POST).