boot - How do I troubleshoot screen configuration failure on a new install?

I installed Ubuntu on a 2008 MacBook Pro yesterday and can't get any display or x server booted. I can boot from the CD into rescue mode, so I can see that:

• The syslog has an error, GdmLocalDisplayFactory: maximum number of X display failures reached: check X server log for errors




• In /var/log/Xorg.1.log (and the other Xorg logs) I see "Fatal server error: [27.266] (EE) no screens found(EE)"




• Earlier in the log out also says "screen 0 deleted because of no matching config section." several times. It also says "Screen(s) found, but none have a usable configuration."

I'm guessing there's a ... screen configuration issue? But I don't know where to start troubleshooting it.

Note: I did discover My computer boots to a black screen, what options do I have to fix it? which I walked through, but holding down right-shift doesn't do anything. It just lands me in a silver screen (light grey, I guess) with an arrow cursor and nothing else.

I can boot to rescue mode from the CD,

Per How do I set 'nomodeset' after I've already installed Ubuntu? Boot into rescue mode, edit /etc/default/grub to add nomodetest and then do update grub.