Help! My New PC Build Won’t Display Anything

I'm currently assembling a new PC and I'm facing a frustrating issue. I've got an ASUS TUF B650E WiFi motherboard, a Corsair Shift PSU, an AMD Ryzen 7 7800X3D CPU, 32GB of RAM from T-Force, an ASUS TUF 5080 GPU, and a Samsung 990 Pro SSD. The CPU cooler I'm using is an Arctic Freeze 3 AIO.

I knocked together a test setup outside of the case to check everything before final assembly. The RGB lights up, which is promising, but I keep getting "no signal" on both of my monitors. I've verified that the display cable is functional and that it's hooked up to the GPU. The motherboard isn't showing any error lights. I'm pretty stuck and unsure of what to try next.