I have an early 2008 MacBook Pro, Santa Rosa model. A few years ago, I upgraded the hard drive to a 7,200 RPM Scorpio drive. For a long time, whenever the computer got too hot, the drive would make a clicking sound and then a beep. My research at the time indicated that some drives did this when they needed to recalibrate due to temperature change. This morning, when I woke my computer from sleep, the contents on the external monitor were frozen (my MPB was closed, in "clam-shell mode"). I powered the computer down. Now when I try to power up, I hear the sound of the hard drive starting to spin up, accompanied by the power/sleep light coming on -- but only for about half a second, and then everything shuts down again. If I continue holding the power button down, the power/sleep light blinks rapidly a few times, but nothing else happens. The MBP's screen never comes on. I disconnected all external devices from the MBP (except for the power cord), with the same results. My initial thought was that the hard drive had crashed (yes, I have a Time Machine backup), but shouldn't the screen still come on with the "sad Mac" icon, allowing me to boot from a start-up DVD or external drive? If it's relevant, the battery hasn't been holding a charge very well, which probably is my fault, since I usually run the computer on AC power, and I hear you're supposed to discharge the battery every month or so. Could it be a power-supply issue? I can take my computer to the Genius Bar, but I'm reluctant to put too much repair money into it because of its age, and it's been a bit sluggish with Aperture, Logic, and big files in any application. I figured I'd check here first to see if anyone has any ideas.