Mac :: 2006 MacBook Won't Start In My System?

I have a 2006 Core Duo MacBook. I shut it down the other day and nothing unusual happened. But, now when I push the power button there's no response at all. Nothing. No lights, no response, no chimes, no screen flicker.Yes, I've read all posts I can find on this and nothing has helped. I've followed the SMC reset (http://support.apple.com/kb/HT3964) and can't zap PRAM since it doesn't even chime. Battery shows a full five lights and the MagSafe cord shows a green LED. I've tried all sorts of booting with just battery, just power, leaving both out overnight but can't get any sort of response. I don't hear any fan motion or HDD whirring up. The power button doesn't seem to be stuck though--it's flush with the case and still gives that slight tactile "click" when depressed. I checked that the RAM's set properly.