THANK YOU KRIS!!!! Sorry I've taken so long to respond to you suggestions.
The
GOOD NEWS is that everything is up and running 100%.
The
BAD NEWS is that I haven't the vaguest clue as to which of your links gave me the solution to the problem.
I swapped drives in, out and back and forth;
I changed jumper settings here, there and everywhere,
I downloaded and up-graded this, that and t'other;
I cursed, cussed and swore;
I checked firmware, PRAM and CUDA;
I sulked, cried and pleaded;
All the above were in random order over several days until Saturday morning when, in sheer desperation;
I crossed my fingers, pushed the power button and held the option key.
BINGO - IT WORKS!!!!!! And, it's been working just fine ever since.
I just wish I could remember what I did Friday night
****Thank you
DL
**** It might have been a Single Malt Solution