(semi-off-topic) I tried to view the Rules and Guidelines back then, to find out whether there were stated expectations about commenters having X amount of legitimate experience, as I've seen that in at least one other tech support venue. BUT "this topic does not exist." And it still doesn't. So, ah...

Hello, here is a shot in the dark: it seems the system freezes solid during its initialization. IMO the low-hanging fruit here is the OS EPROMs, IC32 and IC23. Are they socketed as usual & thus removable? if so, did you try reseating those as well? If that didn't change anything, it's also remotely ...