Hello there, I have an early 2008 2.4GHz 15" MBP with 2GB RAM and it is not booting. I have tried booting from the HDD, booting from the superdrive, and booting externally. None of these work at all and don't get close to booting. What happens is that I have to hold the power button down and the HDD clicks, the superdrive clicks, and the external HDD clicks as well but after a quick high-pitched sound and a short span of time where the activity light is on, then it promptly stops responding. My thought is bad RAM modules but would like some other opinions if possible. Thanks for your time!