I've been building a system for a while, and finally put it together. Yesterday, I turned it on to hear one long beep with some clicks in between. It lasted from about 5 seconds after the fans spun up to when I turned it off. This was without a display connected so I assumed it was an error caused by no display. I connected it to a monitor and turned it on, and the same thing happened. Nothing came up on the display. I listened closely and it was coming from either the bottom of my motherboard or my power supply. My motherboard is a nForce 780i SLI, and my PSU is a CX 500. I have connected everything outside of the case about a week ago, and it went to the BIOS screen because I didn't have a hard drive. No strange noise. Can someone tell me how to fix this?