I have a 24" iMac from early 2008. Of course today is the day it does it's weekly back-up, and yesterday I noticed that it was off (I usually leave the computer on with power save options). When I attempted to turn it on I heard the disk drive make a noise like it was kicking on but that was it. The screen remained black, no start up chime or screen flicker. I unplugged everything and tried again and it is still doing the same thing. Has anyone had any issues similar? I am just hoping it is not the hard drive. Thanks in advance.