@buzz
As I said above "I had to unplug and repower it up, then Retropie won't reboot?"
Therefore, getting any kind of log is not possible.
This person seems to have the exact same issue I'm having so I didn't think it would hurt to jump on the thread.
I'm trying again today, with a new Retropie, and I'm repeating the same issue. I'm taking your advice and being very patient a giving it plenty of time...
Yes,,, I think it's doing something.... I got a black screen now.... I'm being patient... it's not doing anything except being a black screen for a few minutes....
SUCCESS! I hit the "b" button and Retropie is there.
Thanks for your help.