Need some help, mbp won't post

[fongyuen]

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.

 

[fongyuen]

bump

 

[T5BRICK]

Do you have all the screws in the right place? I guess it could be possible that a long one in the wrong spot may be causing a short only when the top case is installed.

 

[fongyuen]

hmm, interesting possibility. I think they are in their original positions. Let me try one at a time.