Hey, I have just come back home and turned on my macbook 2007 model. I was using it fine just 5 minues ago. Then I shut it down.... Now It will not turn on.... I've had 2 hard drives die before (made clicking noises). My 3rd drive was purchased 1 month ago... Is there any way to determine what's wrong? There have been no drops or obvious physical damages. It just will not turn on. There's no signs/lights or error messages. (the battery has charge and the power cord is plugged in) [i dont have apple care] Any tips?