my 2008 17 mbp was getting kinda dusty inside and the fans were constantly running so I decided to open it up, clean it out, remove the factory thermal paste and re-apply some new arctic silver. Everything went well, checked to see if it booted up before putting everything back together and it was fine. But after I re-assembled everything, hit the power button, the chime came on, then nothing. Subsequent hits to the power button would not even evoke the chime. Not sure what to do, I opened it up again to the point where I last knew that it booted up, which was when I took the screws to the cover off and lifted up the keyboard, then it powered on just fine. But after I put everything back together again, it shutdown on me and exhibited the same problem as before. Any ideas as to what I'm doing wrong here? Thanks in advance.