flashing earth - no keyboard, mouse, dvd door will not open - NOTHING-HELP

[biggunz]

flashing earth - no keyboard, mouse, dvd door will not open - NOTHING-HELP

I have no way of inputing anything into the G5 power mac I have - no doors will open, can't use keyboard or mouse. Have rebooted several times, sometimes I get a flashing earth that turns into a flashing earth on start up and then turns into to a steady earth symbol, other times I get a steady earth at startup and then other times I get a question mark. I can not inset disks - not sure what to do here--never happened before - this is the water cooled model--no leaks. I have it run the very very fast with a loud whirling sound - changed keyboards and that seemed to fix it.

[Satcomer]

Hold down the option key while booting. It sounds as if the OS x system is trying to Net Boot to a server. Also see if you can Safe Boot. If you can't Safe Boot then it most likely the hard drive went south, so replace it.