I have an iMac model identifier iMac5,1 with an Intel Core 2 Duo. Over a year ago the hard drive failed so I purchased a new model. Recently I decided to replace the hard drive on my other iMac and upgrade the ram. In doing so installed iStats and discovered the CPU fan is not running. This was probably the reason the original hard drive failed. I purchased a new fan, but unfortunately the new fan does not run either, which leads me to think I have a bad power lead on the motherboard. I have reset the smc and done all the other recommendations I can find from Apple and other blogs, but the fan speed is still 0 rpm when the cpu is at 131 degrees F. Does anyone have other suggestions?