On 2/19/10, Bruce Ryan Nakamura <galilao at lava.net> wrote: > > Instead of a ? mark, one of my G4 MDDs is showing an empty set symbol > on the screen upon start-up and won't fully boot. What does the empty > set symbol mean? It's the prohibitory sign. Amply explained in <http://support.apple.com/kb/TS1892>.