I have built a computer for a friend of mine and upon completion I realized that there is no onboard graphics. I then plugged an hdmi cord into the gpu to display the bios on my monitor but I'm not getting any signal to the monitor. The gpu is running, confirmed by the fan running, and everything else seems to be fine. Is there something I'm missing here that is hindering me from booting from the gpu? Anything I need to do? Thank you to anyone that takes the time to assist.