G4 powermac (mirror door) won't load

[DK8]

It makes a happy "dong" but then I get a grey screen freeze on a screen I know works

 

[Altemose]

@DK8 Is there anything on the gray screen when it freezes?

 

[MacCubed]

It makes a happy "dong" but then I get a grey screen freeze on a screen I know works

What happens if you unplug the hard drive?

 

[DK8]

What happens if you unplug the hard drive?

... I can hold down C and load MacOS CD.

 

[MacCubed]

Most likely the hard drive then, try wiping the drive and reinstalling OS X