No Video Output only when Using a Specific External Video Card

While both another external video card and the onboard graphics work fine, when you try it with a specific external PCIe* video card, there is no video output.

If the tested hardware list (see THOL Builder on this page) does not show the particular graphics card model, either try with the latest board BIOS/Firmware or check with the card manufacturer to see if they have validated the board-card compatibility.