The other week, whilst doing photo editing, my beloved iMac desktop suddenly showed a line on the monitor. Panicking, I quickly turned to Google search to see what to do. This secret has saved my hard drive from being killed … at least for now. I downloaded the recommended smcFanControl and adjusted the fan speeds which immediately started cooling the iMac and the line never reappeared. If you do this, doublecheck before downloading software that it is the correct version for your iMac as well as arranging for Mac fans to be thorougly cleaned of dust and debris.