There is no Bios option for checking Video at POST, but you can set the Bios to „continue on warnings and errors“. That’s Dell‘s way for headless… and you should remove the video card from PCIE slot, not only un-plug the power cord. Otherwise strange quirks can happen.About the video card... after setting everything up, I assume I can just unplug the power to it and still be able to boot with no video? I'll check if there are any BIOS options for checking video at POST, etc, I guess?