No video output from newly build PC

Solution
OK. How about resetting the BIOS (with PC off, unplugged from outlet, pop out little button battery for a minute then restart).

Also, test for a bad stick of RAM: try one stick at a time in each slot.
Take out the GPU and try the on-board graphics per SchizTech. If you still don't get video out, try resetting the CMOS. Unplug the PC from the wall socket. Remove the CMOS battery. Short the CMOS reset pins together for a second (info is in the mobo manual). Put the battery back in. Then, boot up again with the on board graphics. If everything is working, then install the GPU and drivers.