Hi I have the same problem with no image coming out of the DVI socket except with a graphics card plugged into the PCIx16 port BUT I have a 2400Mhz memory module could this be the problem?
This thread is 2 years old with a lot of baggage and no resolution. You should start a new thread and
provide more info on your specific setup and problem. If it works with a GPU it's not a RAM problem.