I can understand your frustration. I've built several gaming rigs for others, and occasionally I get a motherboard that's defective. Bread-boarding it that way can help isolate the problem. And, If you can connect your monitor to the on-board VGA temporarily and use it rather than a video card... and the computer won't show a display, the problem is more than likely the board. It's also possible that the processor is the problem, but I've never had a bad processor yet. I have, on the otherhand, had bad boards.
If you get a display, try to boot to BIOS. If you can enter BIOS and navigate around, then the problem may lie elsewhere.