My Mid-2007 iMac keeps on performing. 20-inch 2.4 GHZ. However, I noticed recently that the Geek Bench scores were dramatically lower, i.e. 20 percent lower than the average. However, if I shutdown the computer for one hour, the scores were well above average. I immediately thought this could be temperature related. I downloaded Mac Fan Control and it is reporting 0 RPM on the CPU Fan. If I manually control it, it stays at 0. I wonder if the fan is shot, or if dirt could clog it to the point it stops? Obviously I need to open it up, sadly my tools and suction cups are probably lost from when I did the hard drive replacement in 2010. Still, I wanted to make sure I wasn't overlooking something first, such as the CPU fan being unreadable on 2007 iMacs or something? Thanks.