I had a problem the other day where my Mac only got as far as displaying the Spotlight icon before it just froze displaying the spinning colour wheel of doom.

My guess was that it was a font issue as I had recently (and stupidly) dragged some fonts from a local server into a Library in Font Book and my guess was that my Mac was trying to find those fonts but couldn’t as it they were on the server.

After searching around (fortunately I had another Mac handy) I found that if you only get as far as the Spotlight icon at startup it is probably because of a corrupt font cache or possible a corrupt Spotlight playlist.

To clear your font cache you need to delete the font caches files which are in your Library folder in the com.apple.ATS folder:

HD/Library/Caches/com.apple.ATS

In here you will find a folder called “System” and other folders with numeric names that relate to other installed fonts. Delete all the folders apart from the “System” folder. When you next start up hopefully everything should be OK.

You could try starting up in Safe Mode by holding down the shift key when booting your Mac (which should in theory disable non system fonts), then delete the font cache files.

If you still can’t boot up, and have another Mac handy, connect them both both a firewire cable and startup your problem Mac in hard disk mode by holding down “t” at startup – you should see a big firewire icon on the screen and the computer should appear as a hard disk on the desktop of your other Mac. You can then get at the font cache files to delete them.