Solid CPU light on X570S motherboard - Won't post - Need assistance

[cmsanii]

I installed a Ryzen 3700x on a Gigabyte X570S Aero G but can't seem to get the system to POST properly. When I turn it on the CPU fan spins and the CPU indicator light goes on then off then the RAM LED goes on then off and then the CPU indicator goes on again and stays on. There is no video output from the gfx card installed. I tried with 4x8GB memory and then tried with a single stick...same results. I am using a DeepCool DQ750-M-V2L 80+ Gold power supply. I tried to reset the CMOS but that didn't help either. The motherboard was previously used by someone else with a 5800x CPU without issue. Any other ideas on what I could try ?