Turns out the Quadra 700 has A/UX installed!! Very cool.

They all work more or less. One LC won't boot. I get the question mark, so it either needs to be reinstalled or at worst a new HD.

One IIsi has a problem that it will shut off immediately after being turned on. Disconnecting the HD power cable and ethernet Nubus card prevents the problem. Either the HD, ethernet Nubus card or the PSU is bad in that one. (More testing/swapping is required to narrow it down.)