Original post by: Dan ,
Clearly something went. Are you upto opening your system to see if you can diagnose what needs to be replaced? Do you have the needed tools and a good work area? Review this IFIXT guide: [guide|999|iMac Intel 20" EMC 2133 & 2210 Inverter Replacement] while I'm not sure this is the problem here it will give you an idea how far you will likely need to go. If you can get the display clear you should be able to see the diagnostic LED's. Here's the IFIXIT technique guide: [guide|7443|iMac Intel 24" EMC 2134 and 2211 Diagnostic LED's]. It should help you isolate out how bad it is. If you are thinking on getting a new system you will want to get to the HD so you can remove it. Then using a universal USB adapter you should be able to salvage your files.