I found another thread that dealt with:

Socket connect failed: Connection refused

One suggestion was to start the machine with just one board hooked up.  I did that and it finally ran without rebooting.  I then tried each board independently.  It would run with each one.  I then noticed that the power cable to the PSU was quite hot. I found another one laying around that was heavier gauge.

Finally I hooked up all three boards again and crossed my fingers.  It started and no more rebooting.  It has been running now for the last 14 hours.  So far so good.