Black screen on G5 Imac

My Imac G5 running 10.5, screen's gone black. When I turn on, The front light glows and I hear the startup Apple mac 'Gooong' sound. However the screen remains black and then within 30-40 secs the light fades. Am I up for a new screen? Maybe something else? Any help or suggestions gratefully received!

[Logic board died....booohooooo

Discontinued March 20, 2006, 5 years use, minimum, I'd say amazing.
Now you have a good excuse for buying a nice new shinny one;-)