Hey, I have iMac 24 intel due core 3.06 4 gb ram nvidia 8800gs 2008. The problem is that it's started to overheat get to 120c and shutting down. The fastet way it gets to shutting down is when I watch video on browser, less then a minute, i can watch video on vlc for hours and it will not pass the 80c. Also when using 3d it gets a bit hot but usually don't get 120 unless it's start beach balling... Anyway, I took it to a authorized lab and at the first test they couldn't see any problem After that they clean everything and ran the apple test and they saw that the hd fan is slow in 600rpm, and they told me that it probably the problem. Before I took it to the lab I backed up using time machine and it didn't Got overheated or something 80c, now they called and told me its the logic board, because the sm something test says about sensor problems. And I need to replace the board, the thing is that I'm not sure about they reliability, because every one I know that went there needed to replace the logic board, I just want to know if it make sense... And if there is something I can do to confirm it. Any ideas will be great. Thanks.