XPS 600 BIOS setup problem

I just replaced my motherboard after the old one died. Plugged everything back in exactly the same way as before and the machine will actually boot and it goes to the dell logo screen, where I have the option to press F2 setup or F12 boot menu. After pressing F2 or F12 it goes to a blank screen with flashing cursor in the top left hand corner. Also diagnostic lights 1 & 2 stay lit on the front console. 1 & 2 are supposed to be bad cards. I took out all PCI cards except the video card and still have the same issue. Same after swapping memory too. Tried clearing the CMOS with same result.

If I unplug all the drives, it gives a drives not found error, but still won't allow me to progress into setup or boot options.