What's the model # of the DRAM? Could it be 4GB total a 2x2GB set? Otherwise if it is a 2x4GB then sounds like a bad stick - pull one boot and see what it shows, then shutdown and try with the other stick, if both boot fine may be a bad slot or bad MC (memory controller) to that might pull the CPU and check it and socket for debris, thermal compound, or bent/broken pins