3 days ago, I shut down my HP Pavillion 7757 media center. When I went to turn it back on, it has *zero response*. (Although, there is a small green light in the back of the tower that is still faintly on). I was on the phone with tech support for 2 hrs. when they decided that I should send my tower in for repair. My fear is that they will wipe out my hard drive, losing all of my family pictures and music (I know, I should have backed it up before). I have heard some on here mention replacing the "power supply." What does this mean? Is it just the power cord? Is this something that I can buy at my local computer store? PLEASE HELP!!