Pardon my ignorance here, finally decided to put together a computer and egads. I purchased a new motherboard, power supply, processor, video card and memory. ASUS M4A79XTD EVO AM3 AMD 790X ATX AMD Motherboard OCZ Fatal1ty OCZ550FTY 550W ATX12V v2.2 / EPS12V SLI Ready 80 PLUS Certified Modular Active PFC Power Supply AMD Phenom II X4 965 Black Edition Deneb 3.4GHz 4 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Quad-Core Processor XFX HD-577A-ZNFC Radeon HD 5770 (Juniper XT) 1GB 128-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card G.SKILL 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Dual Channel Kit Desktop Memory Model F3-12800CL9D-4GBNQ (originally had links for you guys, but I lack the rep, sorry!!) And I've got it all in the tower. I put in power supply, installed processor on motherboard, installed heatsink, put in ram, and I am using an older IDE hard disk. When I start the computer, the monitor tells me "check signal cable." As far as I can tell, the heatsink on the processor is spinning, the power supply is on (obviously), and the green LED on the motherboard is on. I originally only had the bigger output plugged in to the motherboard (what I saw in a YouTube vid as well as the mobo instructions), but after doing some research, it said plug in the other ATX power supply. Which I did. And trying to power the computer results in nothing. No beeps on startup, no post, anyone have any ideas? Your ideas and help is greatly appreciated.