No POST, could outdated BIOS on the motherboard cause readout errors with video readout? Ryzen 9 5900x and asus tuf x570 gaming plus...contacted AMD for boot kit : r/pcmasterrace
Unable to Boot New Desktop System Configured with AMD Ryzen™ Series Processor, and Compatible AMD-Powered Motherboard | AMD
What is the AMD 'Boot Kit' and why you need one for your A320 Ryzen 2200G build - YouTube