On a notebook with Ubuntu 18.04.2 (x86, 32 bit) the boot process has been causing problems since a few days.
Boot problem in detail:
- On startup no grub menu appears.
- The dark purple background typical for Ubuntu without any Ubuntu logo or text appears for several seconds.
- The screen briefly turns black and the notebook restarts automatically.
- The grub menu appears.
- I choose "Ubuntu".
- Ubuntu searches for file system errors.
- Ubuntu boots up.
- The usual Unity 7 desktop appears after a while.
After shutting down and turning on again, the process starts again from the beginning. See syslog.
What is the reason for this problem and how can it be solved?