I made a new build off of mostly new parts (I reused the old PSU), and it is not booting, and I don't know why. Lights come on and fans turn, but that beep doesn't happen and the monitor doesn't receive a signal. My motherboard has this thing called Dr. Debug (on ASRock motherboards), which shows 00, but doesn't correspond that to any problem. Any ideas anyone?
Try booting with just the CPU, videocard, and 1 stick of ram to see if it comes up. Also try reseating the components and cables in case somethin is not sitting right. If not, maybe try resetting the BIOS on the system board as well to see if that makes a difference.