I can not for the life of me to get into open firmware. I have tried the CMD + Opt + O + F before the chime, after the chime, and during power up. I know the keyboard buttons work since it works when it boots into OSX. Tried PRAM reset but that does not even work either. I researched and found that maybe the open firmware had been locked. I tried running Open_Firmware_Password.dmg and it does not even load. OS is 10.4.11 / iBook G4 1.3. What am I doing wrong ? I am trying to reload the OS using USB.