I have an XFX 680i LT, and up until a few days ago it had been fine for a year. My computer starts up, but there is no signal to my monitor. I did a graphics card swap, memory swap, hard drive swap, and CPU swap, but nothing worked. My power supply is working, otherwise there would be no power to my computer when there is. I didn't think it was my motherboard because the onboard fans and my CPU fan have power, but at this point that's the only piece of hardware left that could be causing a problem. Is it my motherboard or something else?