Mounting PC - no screen and no beep

I have a little problem with my newly assembled computer. I well mounted it but when I try for the first time, no beep and my screen remains still. The LED on the motherboard is well fed and all the fan running. I tried

- removal of strips of ram
- tries to take 2 dvi output on the graphics card
- dismantling of the graphics card
- tries to take another pci express

My config:

Asus deluxe p6t
4 GB of DDR3 ram
Sapphire 4870x2
PSU 850 corsair
hdd Raptor 150 GB
hdd 1TB Samsung
Processor Intel core i7 920

Begin by removing all the unnecessary things (including hard drives and leave a single RAM stick).

Check that your speaker is plugged into your motherboard and you well-fed all the right things: your motherboard via the 24 pins (that's for sure given that the LED lights up) and 'any additional connector, and your graphics card.

Clear CMOS. Try again starting to see what happens.

If it does not change and you have another power supply, try to replace it to see if they change this time is something.

Finally, remove the RAM and / or graphics card to see if they will start to beep.

If you do not if only a few beeps, I expect a motherboard or a defective processor.

I have tried removing the ram and it beep several times when I take the two strips. I also tried removing all the hdd and drive and still nothing so sure that a strip of ram.

Try to reset the ram and remove the graphics card to see if they will start to beep.

Otherwise, several possibilities:
- This may be the graphics card problem.
- Incompatibility between your RAM and your motherboard.
- Screen problem
...
Not easy to diagnose in your case, unless you have another machine allowing you to test your components (graphics card and RAM for example).

Just an idea in passing, try to flash your bios with the latest version (should be possible with a usb key) and restart rule the frequency of your ram still in the bios.