Troubleshooting No Signal from Motherboard Display Ports on New PC Build

I'm building an office PC for my father-in-law, and it's been a bit of a challenge with several issues. I've managed to resolve most of them, but I'm stuck on the latest one. Here's what I've got: an Intel I5 11400 CPU, an ASUS H510M K motherboard, 32GB of Corsair DDR4 RAM, a 500W Thermaltake PSU, and a reused 256GB M.2 NVME SSD from an old PC. The system posts and the fans settle down, but no signal comes through either the VGA or HDMI ports on the motherboard. I've tested multiple cables and monitors to rule those out. I also reset the CMOS by shorting the pins and removing the battery for ten minutes, but that didn't help. I tried using an RTX 2060 from another PC in the PCIe slot, and it worked fine, allowing me to access the BIOS. I've verified that I indeed bought an I5-11400 and not an 11400F, as the CPU box confirms it has integrated graphics. When I put the GPU back and connect the monitor again to the motherboard's HDMI and VGA, there's still no signal. I'm at a loss and wonder if it could be a solder issue on the display ports or if I accidentally received an 11400F instead of the 11400. Does anyone have other ideas on what might be going wrong?