🚀 go-pugleaf

I am having a puzzling problem with a uVAX-3 I recently purchased.  The
system is made of a BA123, KA650, (3)MS650, TQK50/TK50, 8 plane VCB02,
VR290 and a Emulex QD32.  When I first got the system the VCB02 worked
but I had a problem with the TK50, so the system was never on for long
but it was powered up and down servial times.  After the TK50 problem
was fixed I was formating the drives via the QD32 (takes a while) and
the VCB02/VR290 stopped working.  I had a RS232 console cable, and just
unpluged the cable to the VR290, pluged in a VT220 and reformated the
drives.  A day or so later I went back to load software and the system
would not come up, the CPU card stalled in selftest 3.  I found that
removing the VCB02 card set allowed me to boot the system, so I aranged
a swap of the VCB02 card set.  Same results with the new card set.
I am stumped, what am I missing?  I am 100% certain that the system
booted more that once with the VCB02 card set still in the back plane
the night it first failed.  One more item, the original VCB02 card set
checked out OK when it was returned.  The party I got the system from
thinks that the next step is swapping the VR290, but I can't see how a
bad VR290 could cause the problem I am seeing.