Asus Z78 Ram Slots Shorting out

I got a new motherboard, Asus Z78 Deluxe Dual. The problem is, only one of the ram slots work (slot 4) and if I insert ram in any other slot, the computer turns on for 2 seconds and turns off again. It seems like a short circuit. I took the motherboard out of the case and placed it on the motherboard box to try and see if that helps but it still turns off. I reset the bios to factory defaults and still no progress. Is it possible that my motherboard is faulty? If it is, would I be able to return it for a new one? I got the motherboard from Ebuyer, a UK online electronics store. I used different pairs of ram, I used a Crucial Ballistix 1600Mhz DDR3 4GB stick and a G-Skill Ripjaws 1600Mhz DDR3 4GB stick separately. Any ideas on what the problem may be?

could be the mismatched memory, maybe turn off dual channel memory

No, I put one ram stick on each test boot, so one Crucial Ballistix stick on 1 slot and boot

Z87 i suppose?

Anyway it looks like a problem with the motherboard indeed.
i would suggest to send it back for RMA.

If you have a small air compressor, i would try and blow any dust that might be in the memory slot, and the reverse of the motherboard around that area and maybe the whole thing while I am at it. As one last thing before returning it. Using an anti static mat etc