Water can be perniciously persistent and penetrative. It can soak in under and between components and remain trapped in there for days until driven out by heat or dry air.
When you say "No boot" - what are the exact symptoms? Do you get any signs of life at all? Drives spinning up, lights, etc. The reason I ask is that stripping this machine could well be premature - it may be as simple as needing a new motherboard battery, or a power supply. This "zip sound" of which you speak doesn't tell us much.
don't even think the PowerMac and the Video thingy went together TBH
Top of the line, several thousand dollar PowerMac with dual drives and multiple Nubus/RAM upgrades (as would have been found in many a mid-late '90s video production shop), and a "Video serve thingy". My money is very much on them belonging together, and at least one of your cards being useless without that box.
a capture board (now missing its breakout box) it is kind of useless
One PCI video card with slots for Dimms.
There's no PCI in an 8100. That'll be a PDS card.
Nubus Video DB-15 and what (looks like) a VGA Input. It is female. On the same board is a DB-15 Output
*sigh*
I am unsure of everything. Haha
Perhaps you should seek advice before acting, then.