@mattsoft and @joshc Right you are: after closer inspection, I do see some corrosion near the caps on both IIcis. Thankfully, the corrosion looks superficial, so hopefully the caps will be the only thing needing replacement. So recapping will be my next step!
@aeberbach Ah, the Open Source Scan Converter looks excellent! Unfortunately, a bit out of my price range at the moment, though it's definitely on my wishlist now. If anyone owns one in the greater Pittsburgh area and would be willing to let me borrow theirs, just let me know!
@max1zzz Good to know that the batteries probably aren't needed. Looks like it is an accelerator card! I've attached photos of all the expansion cards:
Those drives are the most unreliable ones I have ever seen.
Out of 10... 9 are bad, moreover the unusual board and connector was only used in the Portable.
You can lift the cover to prevent the seal from going bad, but there’s a risk to contaminate the platter as well.