First, and sorry if this is overly obvious, check and be sure that everything is seated and connected properly. Read the motherboard manual carefully. Be sure all the required power connectors are plugged in where needed, including the video card. Pay special attention to the installation of the i7 processor and fan. Lots of folks have trouble with that latch.
When you power the computer on, do you get a POST beep? This is a single beep about 10 seconds after you power on.
If you are not getting a POST beep then your problem is "core component" based: Motherboard, Processor, Memory, Video card, power supply.
The usual diagnostic test for core component trouble is to disconnect everything from the motherboard except the processor and proper power cables. Turn on the computer. It should start beeping after POST with a "no memory installed" beep code.
Power down, install one stick of memory, and restart. You should now get a new beep code: "no video card".
Power down, install the video card, and restart. You should get the bios info on your screen.
Power down, and add the rest of the memory back.
(Some people do this diagnostic with the motherboard out of the case - on an anti-static surface. This eliminates some kind of short-circuiting that can happen if the motherboard posts are not installed correctly)
You are simply trying to narrow down the problem by process of elimination. If at any point you do not get the expected beep code or video signal you can deduce that the last component installed is at fault.
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If you can POST then you may need to look at some different diagnostics for that video card.
Try it in a different slot.
Try it with just one stick of memory installed.
Try it with a different VGA cable, one with pin 9 omitted, or if your current cable has all 15 pins, try one with only 14 pins (pin 9 omitted).
Borrow a monitor and test.
Borrow a known good video card and test.
Hope that helps.
