My Xubuntu 14.04 installation stopped booting all of a sudden: after rebooting I just see a flashing
_ in the top left corner of the screen. Holding
Left-Shift during boot won't open any menu,
Ctrl+Alt+F* will not open a terminal I can type in.
I've reset BIOS settings, which did not help, then made a bootable USB stick with Ubuntu. I can now boot and I see that the data on the disk with OS is intact, I've checked the disk with
badblocks and it found no errors.
Is there any way I can locate any details as to why the system does not boot?