Yes, your signature line is possible. iMac G5s were notorious for bad power supplies, and capacitor issues. Apple did have an extended repair program that went beyond the warranty that has long since expired. You can remove the hard drive from the iMac G5 and put it in a Newertech case and read off of it on a newer Mac. But migrating to a newer Mac, you'll be faced with this issues:
http://www.ifixit.com/ has directions for carefully removing the hard drive.