Might start with checking the boot log to see if something failed.
Code:
less /var/log/boot.log
Should end with "Starting Authorization Manager..."
If it stops at another point we may be able to help you determine what happened.
I ran across an issue where my home server was running a fsck across a 4TB volume on every reboot but not on cold boots, this resolved itself after an update.
If you reboot the system when the loading 'f' shows up pressing alt+d (I think) will display the verbose output hidden behind the splash screen.
Hope this helps you troubleshoot the issue.