Hi I have a friends mac book pro (15 inch, purchased in 2008) and it overheated due to the vents being clogged with dust. I took the motherboard and removed all dust, but it still does the same thing and powers right off. What exactly happens is I hit the power button and the fans spin for about two seconds then they stop. As the fans stop I can also hear the hard drive losing power. Nothing shows on the screen because I believe it looses power before the screen can even load anything. I tried swapping out the ram and disconnecting the cd rom and trying to boot it up (i saw a post where the cd rom caused the laptop to not power up thats why i tried that). I am pretty sure it overheated because the fan on the right hand side was 95% clogged with dust and the fan on the left side was about 75% clogged with dust. The dust was about 1/4 an inch thick (at the thickest point) between the grill and the fan. A while back I fixed a broken laptop (it was a pc however) that overheated- the screen went blank so I removed the board and reworked the GPU with a hot air gun and it fixed the problem. So if I was going to try a reflow with this one I was wondering if anyone knows what chip I should try it on? Any info would be appreciated. ps- laptop mother board is model 820-2249-A.