Created another thread with a more concise question... My Power Supply temp sensor fluctuates wildly causing improper fan engagement. Usually from 40ºC - 80ºC, depending on if the trackpad is moved around. Very odd. My guess is that it's on the DC-in board, but I don't want to buy one unless I *know* it is the problem. If its on the logic board, it would help knowing that too. Hope someone can help! Photobucket Video, turn up the volume so you can hear the fans going as I scroll: When I scroll, the temp sensor spikes to 75-80ºC, causing fan engagement. When I let off, the temp sensor goes back down, turning the fan off. I have no idea what the actual temperature is around this sensor, unfortunately.