So I used this site: appleserialnumberinfo to find out some extra details about a machine that's come into my possession. It says I should have 4 RAM slots, I have 8. I'm confused. It is: Dual G5 1.8, AGP. Back panel has: 1xFW800, 1xFW400, 2xUSB, 1xOptical in & 1xOut Etc. PSU needs replacing (AFAIK, plugged in & dosn't even spin a fan). Wanted to know the Wattage (but not sure that it's important?) before I eBay for one (& an Airport card too). I think it might have had a logic board replacement maybe at some point, would explain why it dosn't match the Spec. (plus is cleaner then the rest of the machine). Any help would be good. Thanks! J.