I have a G4 Digital Audio. Since i installed a 1,7GHz procesor upgrade (Sonnet Encore) and had to apply a patch to the firmware it seems that open firmware password protection is enabled. Now i'm in trouble as i can't start up from a selected disk (i didn't consider it's on a > 128 GByte partition) and as i don't know the password (i haven't enabled it) i can't use the option key, so i can't startup the computer from any disk. Reading this: http://docs.info.apple.com/article.html?artnum=106482 i realized about the password protection and that there may be a way to bypass it having fisical access to the computer. Any hint what i can try to start up my computer again?
There is a way to do that, but to help others avoid having their Mac's security breached (particularly those with laptop machines) it is not publicized. You should contact Apple Support by phone, or take your machine to an AASP.