Why won't my screen get signal ?

Remove the extra HDD. System may be trying to boot from it with no or corrupt OS on it.

It's not the video card nor a compatibility issue between the video card and motherboard cause if it was it wouldn't have worked with the stripped down config you used to get the OS installed.

When testing/troubleshooting you ALWAYS add or remove 1 component at a time. Not a "shotgun" approach.

This should be tatooed, in reverse, on the foreheads of all new builders, so that every time they look in a mirror, they read it!

Guys, I realize that the human tendency is: you (hopefully) spent weeks reading manuals and reviews to pick your components; you figured out how to 'pry it into' your budget; you got an adrenaline rush placing the order on NewEgg; you obsessed for a day or two, checking your email every hour for the shipping confirmation; you logged onto UPS to track your order enough times to have their logo 'burned into' your screen; and now, the 'big brown truck' has left a BIG pile of cardboard boxes on your porch - you wanna rip open those boxes helter-skelter, slap that baby together, and be playing grand theft auto on it tonight! FIGHT THAT! ...Sit down. Take a few deep breaths. Have a beer. (Or, if you're a manic-depresive addict like me, take an extra anti-psychotic!) THINK! The next few days (if you're not planning on overclocking), or weeks (if you are), will be critical to the success, stability, and utility of a toy that you'll likely be living with for YEARS! 'Breadboard' the MOBO out of the case for your first tests. Be painstaking about your HSF install - do diagonally opposite pins first, then the other pair; it's more difficult than just 'working your way around', but it results in a much better install. If you missed downloading any of the manuals before you ordered (and my policy is to never buy anything whose manufacturer does not make the manuals available on their product website - if they can't be bothered, what kind of support do you really expect from them?), NOW is the time to read 'em - ALL! Do that "Load Optimized Defaults" first thing when you get video. Test everything! MemTest those DIMMs one at a time, for several passes, so you won't be suspecting them, or fiddling with them later... Don't freak out if you get a bad component - 'infant mortality' happens - deal with it - now's the time, before it goes in the case, while it's relatively easy to deal with... TRUST ME - you'll thank me later - a little patience now will go a long way toward years of satisfaction with a well-done piece of equipment!