When I updated the software today, using Ubuntu 20.04.1, and restarted, it failed to reboot or show a login screen. Instead, I get this message:
/dev/sda2: clean, 280773/19505152 files, 7038094/78011392 blocks
Then the text disappears and leaves a blinking cursor in the top left of the screen. Nothing happens when I type.
I am using an iMac from 2009. Processor: 2.66 GHz Intel Core 2 Duo. It is dedicated to Linux, not partitioned.
Looking for solutions, I tried hitting Ctrl + Alt+ F2. This got me through to a login, but it is not recognising the username as I remember it (I am the sole user, and with the normal login screen it shows my name, so I hoped that would be straightforward).
I tried restarting and holding down left shift, or right shift, or Esc, or Tab: the Grub menu does not appear.
I have tried booting with a USB stick which I originally used to install the system.
I have also tried booting with another USB stick onto which I copied Boot Repair Disk.
Am I missing something simple?