Greetings,
Without looking at your hardware specifically, the following may help:
-Ensure the 12v rail on your PSU has at least the minimum number of amps required for the card
-Ensure you have power (PCIe) connected to the card if required
-Ensure the system BIOS is configured for external card as first display device. If your BIOS has different Gen_ settings for video, you can experiment with these also. You can use the on-board video to get to these settings if needed.
If all fails, confirm you are running the latest BIOS available for your board.