I was running Ubuntu 11.10, and upgraded to 12.04. After the system rebooted, it began exhibiting the following behaviour:
1) It loads the BIOS. I can access the BIOS menu, so I can select what piece of hardware the computer boots from if I need to. 2) The screen turns purple. 3) The screen turns black.
Mashing ESC, DEL, etc does nothing after phase 1; in fact, the keyboard and mouse are totally unresponsive. I cannot even turn numlock off and on.
I tried loading from a Super Grub 2 disc, but while it can detect some two dozen kernels, none of them seem to load properly. I am booting from a Live CD now, but I'm not sure how I should go about fixing this.