[mamorim01]

There seems to be an alert which I have been unable to identify or address so far

Well, it mentions "MB.BAT.V_BAT" which suggests to me "MotherBoard battery voltage".  So it's probably just a matter of replacing the coin cell battery with a fresh one.

Yup. That did the trick! The cell battery was indeed dry. I had just dropped the processor in the socket so I was a bit worried that it might have to do with an incorrect voltage setting driven by a motherboard jumper, but it turns out there is little to no configuration needed on that front.

I am pleasantly surprised at how useful the diagnostic tools are, once you get in detail. One of the four DIMM modules I brought over from the Blade 2500 is definitely faulty, the system was able to pinpoint the exact location without a sweat.

Still pending to install the second CPU as I do not have a spare heatsink, but it boots!