Re: Black screen after booting from GRUB
If you are still wanting Ubuntu, try pressing: 'Ctrl_Alt+F1' from the blank Screen.
It should give you a text terminal or TTY, where you can log in and do all sorts of things.
For example running 'startx' may give you a GUI Screen and/or a lot of error messages indicating what is wrong.
Post back what you get and for further instructions. Give details of your set-up & OS version.
"Better Solutions may bring Worsened Problems": After Lao Tse, b. circa 405BC. a contemporary of Confucius, who died circa 600BC.
They did things differently in those days, apparently!!