Well my Macbook is about a month away from becoming two years old. A little bit ago, it started a grinding noise. It seems to be only whenever I first turn it on, or when I wake it up. To be honest, it sounds like a timer like in Guesstures, or Scattergories where it makes it audible so everyone knows when it stops, times up. It stops after a couple min. and it's loudest at the vents near the screen. To be clear, this is different from the disk drive noise when it wakes up, the one that lasts no more than three seconds. I've read about this on other threads, some say it's normal, others say take it in. I hope this computer doesn't short out on me any time soon, but if it does, I'll have to get a refurb Macbook Pro. Anyone know what this is, and anyway to stop it?