Finally plugged in the 3B2/400 I’m attempting to restore. Power supply immediately let out the magic smoke. Nothing is visually damaged, but I did find a bad (shorted) TIP41 power transistor. Lots more testing and debugging to do.
Also discovered a CR304 rectifier diode that failed short, probably took the TIP41 with it. I'm going to recap it while I have it all splayed apart on my workbench. So, $55.92 later, I have a big DigiKey order coming my way. We'll get it working again.
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko