Well. Boo. I did the thermal paste clean-up and it really did not seem too hard. I had a lot of paste in there. Put the computer back together. Press power. Start-up chime... small progress bar. Shuts off to black screen. Less than ideal. Zap the PRAM, tried to reset the SMC, to no effect. Took everything apart, retraced my steps. Seems ok. I'm pretty certain everything is assembled correctly and all the little cables are plugged back in. Reassemble, no boot. Any ideas on what to check? I don't have a Y screwdriver to remove the battery. Any other way to reset this laptop? What is weird is, it kinda booted before, getting to the progress bar. Now it's just not responsive at all. Sigh.