Sorry for reviving this old thread. I'm new here (just picked up two d8b units yesterday), and just wanted to report that I had the same symptom as Wadro above ("Loading MackieOS... then screen goes blank and Error 43), and it was also caused by the harddrive.
I swapped harddrives between the two CPUs, and it booted up just fine.
I figured this might help someone else struggling with the same kind of problem without wasting as much time as I did (I reseated all PCI/ISA cards in the CPU and ribbon connectors in the console first, which I think wasn't necessary in my case).
Now to explore my new/old toy...