After pulling all the cards, drives, etc, I've narrowed it down to the Nexus hard card (unfortunately). It will boot about half the time, otherwise just give me a grey screen. It was a little tricky since it still boots every so often with the card still in.
I'm guessing I can just move the hard drive to a different card?
Anyway, when I finally saw the disk prompt screen *finally* show up I was elated. I mean, I knew the night was blown since I would do nothing but tinker with the thing.