I recently had my 2008 Macbook Pro's logic board replaced at the Apple store after the graphics card failed. They replaced it for me free of charge as the graphics card is known to have a higher than usual failure rate. I was very pleased to have this part replaced free of charge as my computer was out of warranty. However, my fans now run at full speed all the time (around 6000 RPM) and my computer runs hotter than normal. It has even shut down a few times on it's own; which scared me. I checked the thermal sensors to see if Apple had neglected to properly connect them, but they look good. I'm going to replace them anyway to see if it makes any difference. What else can I do? I don't want to bring it back to the store to have them tell me the fan noise and heat is "normal." And I don't want to pay Apple to do something I can do myself. Would replacing the thermal paste on the heat sinks help this? What else could I do? Thanks!