Continuing the discussion from Grub theme is too slow:
I'm leery posting this as a step-by-step howto because grub, frankly, scares me with all the changes I've been wrestling with the last few years. I'd hate to see a new user make his system unbootable.
Things like config files scattered helter-skelter, tweaks and comments edited by distros that are flat wrong (not UM BTW), deprecated things with no replacements. It's my rage topic.
That said, the way I solve a lot of issues is get grub out of graphics mode like this (remember it's not detailed step-by-step):
edit /etc/default/grub as root
Uncomment the line so GRUB_TERMINAL=console is active
run update-grub as root
Grub will now be in a TEXT mode, like a console. You don't even have to uninstall grub themes.
Drawbacks? Comments? Anyone else doing this?