PLEASE HELP! MAC WONT TURN ON!!!!

Question

My fellow mac users, I am hoping that ya'lls wisdom can solve this problem I just encountered a few days ago. I have a White Macbook 13inch and have had it since 2008. I just recently upgraded everything. New 320gb hard drive, 2gb RAM, Snow Leopard, and iLife 2011. I have been using it all for a month now and everything is running beautifully.
Last week, I turned my computer off, as usual for the night and when I woke, the computer would not turn on with the power button. I opened up the computer and dusted it and still nothing. I ordered a replacement keyboard from ebay and plugged it in and low-and-behold, It turned on. I wanted to make sure that the original keyboard was broken so I plugged that one in and it worked as well. Including the power button.
Now I just tried to plug the new one in and it doesn't work at all. But the original does. I am worried if I turn off the computer again, I won't be able to get the mac back on. If anyone has ANY suggestions, they would be most appreciated. I don't want to take it to Apple because I know they will charge me $400 for this computer and I clearly don't have that. Any advice would be most gracious!
Thank You!

Answer 1

Did your replacement regimen include a new battery? Have you ever calibrated the battery? : http://docs.info.apple.com/article.html?path=Mac/10.6/en/9036.html
Reset the SMC? : http://support.apple.com/kb/HT3964?viewlocale=en_US
Does it start normally when the battery is removed entirely?
Does the Magsafe adapter still show a green light when connected and fully charged?
To check the number of cycles and 'health' of your battery, click on Apple in the menu bar, About This Mac, More Info, and Power. 'Average' lifespan of the standard battery is considered to be about 300 cycles, and a removable MacBook battery typically registers at least 4800-5000 mAh fully charged when brand new.
Last possibility that comes to mind is that you're wearing out the power switch if you indeed turn it off every night. In my experience, OS X is stable enough that I often leave mine run for weeks without a restart. I just close the lid when I'm not using it.
Message was edited by: kostby