My wife has an iMac G5 (I have an Intel iMac) that suddenly will not boot up. I inserted the OS 10.4 install disk and held down the C key. No luck. Goes to the grey screen with the Apple and the slowly revolving pinwheel (not the color one). After a few minutes all the cooling fans come on at high speed. Nothing further happens. Now I can't get the DVD out either. How do I do that?