NO DISPLAY - Problem Solved.
Cleaning (scraping) as suspect battery terminal brought mine back to life.
The terminals looked OK, but there was one with the slightest hint of corrosion.
I scraped it clean with a small flat blade screwdriver, inserted the good tested batteries and it booted up.
The voltage between the positive end of the left battery and the negative end of the right battery when viewed with the batteries closest to you should be +6.3 VDC with fresh batteries.
Thanks for the corrosion tip below, it worked for me. I would not have gotten any further had I opened it and poked around.