At work, we have a 17" G5 iMac from back before the iSight was put in. We're an Apple shop, so we have the new iMac actually on the floor for people to try out. The old G5 this thread is addressing is up on a shelf, but we want to turn it on as a display model. We plug a temporary mouse and keyboard into it, but the machine never gets past the white Apple screen with the "I'm thinking" animation. After a minute or two, the fan turns on full blast, but the white screen remains without any signs of moving on. What is our problem? Dan.