Windows 7 - New Computer, black screen + GPU Fan at max speed

Hey, just put together a new computer and I'm having trouble booting it up. All the lights on the MoBo, and the fans are running, the fan on my GPU seems like its going at max speed.

When I try to start up, the computer starts, then turns off for about 2 seconds, then starts up again, and stays on until i turn it off. Theres only 1 short beep when I start it up.
I am using a HDMI cable from my monitor to my graphics card, and it just says " no signal "

Heres the new system i've put together.
ASUS Maximus IV Extreme-Z, Socket-1155
E-ATX, Z68, DDR3, 4xPCIe(2.0)x16, CFX&SLI, NF200, SATA 6Gb/s, USB 3.0,EFI


Corsair SSD Force Series™ 3, 60GB
SATA 6 Gb/s (SATA3.0), 550MB/490MB/s read/write, SandForce® SF-2200


Corsair TX V2 850W PSU
ATX 12V V2.3, 80 Plus Bronze, Standard. 4x 6+2-pin PCIe, 8x SATA,
140mm fan

Corsair Vengeance™ DDR3 1600MHz 8GB CL9
Kit w/2x 4GB XMS3 modules, CL9-9-9-24, 1.5V, Vengeance Heatspreader,
240 pin

Intel® Core i7-2600K Processor
Socket-LGA1155, Quad Core, 3.4Ghz, 8MB, 95W, Boxed w/fan


XFX Radeon HD 6970 2GB GDDR5
PCI-Express 2.1, 2xDVI, HDMI, 2xmini-DisplayPort, 880MHz

All help is appreciated!

First of all search for beep codes for your MB, # of beeps will tell you what fails during bootup. I build quiet few desktops myself and usually in case like yours is good to recheck all the connections, especially seating of the video card, more than once the card seemed to be in but not really. Also all the power supply cables, RAM and pretty much redo whole assembly from scratch. Also it's often helpful to boot computer with minimum components: for example disconnect hard drive and it should still get you into BIOS and to "can't find boot drive" message, but the beep and no video at all would indicate it stops at the very beginning of sequence and that's where beep codes are helpful. Could be one of the components is not compatible or outright broken also.

Thanks for the reply! I already tried taking out the RAM, I also tried reseating the graphicscard in different slots.
The system is "running" as in - , it turns on for 2 seconds, turns off, then turns on and lets off 1 beep, then it just runs, with GPU fan speed at max.
I tried disconnecting all USB devices + the hdmi cable aswell, still runs the same.

Can you get into your BIOS? Do you have a DVI cable for monitor connection?

I can't see anything on my monitor, so no .

Does your mobo have a VGA/DVI connections? If so try connecting your monitor to one of those ports.

Question; have you installed your drivers from the mobo cd/dvd?

I've solved it now, the problem was that I couldn't even get a signal on my monitor, no way I couldve installed any cd/dvd's, as i didnt have an operating system. This computer is _brand_ new, never been run before, and i figured out the problem.

Simply put, i forgot to connect the 12V ATX to support the CPU, this made my GPU (for some reason) run at 100% and no signal, after i connected correctly this was all fixed. Computer is up and running now

That's what I was about to type! Lol classic mistake

I did that and rebuilt my last rig like 4 times... Then was like "ohhhh"