I recapped everything that was electrolytic capacitors. Exact same microfarad ratings, and +105 celcius rated (higher quality caps).

There's not a single cracked solder joint, I've been through the entire machine for hours checking for dried/cracked joints. I did find some initially, but they're all restored now. Restored as in fully remove old solder, clean up flux, add new leaded w/ flux solder. I've also checked that the thick green ground wire going from the PSU case to the SE/30 chassis is good.

I'll try cleaning the connectors, I'll keep you updated on how it goes.