Pat,
The last one (Bitx40 I built a few months back) I had put the display connection in on the wrong set of pins, a common issue with the current instructions.
I would check to make sure its in the right spot (post a pic maybe). It sounds like the nano is dead, I had the very same issues. Boots, screen on, black squares....death everything went blank.
While the nano leds will still work the rest is dead.
If you haven't get a spare nano clone or otherwise and try flashing the firmware before even plugging it into the radio.
Hope that helps
73
--
David
?N8DAH
N8DAH