That usually happens when the wrong resolution is set... could be a driver configuration issue, the driver itself, or a kernel setting which is invoked when the bootloader entry is selected.
You could try setting nomodeset
in your kernel boot line;
See here for more info on how to do that: http://ubuntuforums.org/showthread.php?t=1613132
This should at least get you to a console so you can reinstall/change the graphics driver.
It might also be fixed by simply adjusting the VGA
parameter, which is used to change the resolution of the consoles. Ie; VGA=ask, VGA=none, VGA=792, etc.