System won't boot, flashing globe!?

[rrsub]

Rebooted a system that had no problems and now all I get is a flashing square with a globe inside of it.

Ran Norton Systemworks, fixed a few errors and the report said it was fine.

What gives??

 

[rrsub]

Update--

Turn on sysrem get the flashing globe for 5 minutes

After that, there is a folder alternating between the Finder icon and a question mark for 5 more minutes

After that, the system boots.

It's not anything on the harddrive, it's system specific. I switched out HDD's

 

[nrb501]

Have you tried resetting the PRAM?

 

[rrsub]

How do I do that?

 

[rrsub]

Apple-Command-P-R didn't do anything.

 

[rrsub]

Told the OS to change the startup disk to the local harddrive. No reason for it to be changed to the network disk but it was.

 

[Guest_imported]

It sounds like a CUDA problem? Even some of the iMacs had a CUDA switch! Its a round and elevated circular button on the logicboard near the power? Hold it down for a few seconds, it'll kill your machine, but it corrects many problems?