New build having trouble getting the monitor to start when turning on the PC (help pls)

I've had this same issue with my old PC (10 years old) before I built this one. I'm using the same HDMI cable that I used with the old one, and when it happened on the old PC, I'd have to remove and replug the HDMI cable to get it to work. I always thought the issue was with the PC's connectors, not the cord. But maybe I was wrong? Any suggestions? Pic of my (mostly unlit) new build for tax

I've had this same issue with my old PC (10 years old) before I built this one. I'm using the same HDMI cable that I used with the old one, and when it happened on the old PC, I'd have to remove and replug the HDMI cable to get it to work. I always thought the issue was with the PC's connectors, not the cord. But maybe I was wrong? Any suggestions? Pic of my (mostly unlit) new build for tax