I recently attempted to upgrade from Ubuntu 12 to Ubuntu 13.04.
Upon restart, I get a quick flash of the Ubuntu logo, and then the screen goes black. It stays that way until I restart the device.
I have tried to install a different OS, but it doesn't boot and tells me "no operating system" or "missing operating system". I have gone into the Grub sub menu and tried to enter commands that people suggest on forms and nothing works.