Help! My First AMD Build Is Just a Black Screen – What Could Be Wrong?

I just built my first PC with an AMD Ryzen 5 8600G and I'm facing a serious issue. After finishing the build, when I power it on, all I see is a black screen. The only sign of life is the CPU fan spinning. Here are my specs: - AMD Ryzen 5 8600G with Wraith Stealth Cooler - ASUS Prime A620M-A (microATX) motherboard - Crucial Pro DDR5 RAM (2x16 GB, 5600) - Gigabyte AMD Radeon RX7600XT graphics card - Kingston NVMe PCIe 1TB m.2 NV3 for storage - Corsair CX750 ATX 750W PSU - NZXT H5 Flow RGB Compact case The motherboard doesn't have any POST lights, which makes troubleshooting tough. It does have a BIOS flashback light that blinks when the button is pressed, but that's it. When I turn on the PC, the RGB lights activate and the case fans spin briefly before stopping, while the CPU cooler continues to run. I get no beeps from the motherboard at all, and the QLED lights that should indicate POST issues aren't flashing either—they only show a solid light which the manual says means everything's fine. There's also no output on the monitor; my RGB mouse and keyboard don't light up either when plugged in. However, I can tell there's power to the USB ports since my phone and flash drive respond when connected. I even tried removing all the RAM to see if that would trigger a POST error, but nothing changed—no QLED lights flashing at all. I've plugged in speakers to listen for POST beeping but heard nothing. The PSU fans are running, so I don't suspect it's faulty. I'm beginning to think the motherboard might be defective and needs replacing. Any advice would be greatly appreciated; I spent quite a bit on this build and I'm past the return window for the motherboard!