1st Reboot after fresh Yosemite Install - Chime + Apple logo + status bar...then status bar goes about 1/3 of the way and then it dissappers along with the logo and I get just the white screen.  

When I boot into Safe Mode I have no audio and sometime the screen flickers.  I looks like it flickering rolling up the screen.  It's weird.

I've tried two different HD's and created to different USB installeation disks.
I've reset PRAM and NVRAM.

I'm stumped.
Might it be a Macbook Pro from 2010 to 2012 that you performed the installation on? It sounds an awful lot like the motherboard issue that these models suffer from....