Hi guys, me again. I'm trying to solve a fan problem, and whittled it down to this: When idle, and right from the moment the on button is pressed: One fan is noisy - because it's rotating at, or somewhere near, maximum rpm (circa 3200). However, Hardware Monitor reports it as operating at minimum rpm (circa 500rpm). Hardware Monitor reports all fans as operating around minimum rpm when computer is idle, which seems totally correct, apart from this errant lower front cpu intake fan. I've tried a replacement fan unit - it does the same thing. I've tried just about every conceivable obvious thing - stripping down all connections and RAM, even erasing the HD and starting with no OS installed. I've reset the pram and the other thing. If Hardware Monitor can't spot it, what does that mean/not mean? I'd like to run the hardware test, but don't have the original discs that came with the computer, only an apple leopard install dvd which doesn't seem to do it.