SOLVED: Power supply was the issue, got a replacement from the list of compatible power supplies on the motherboard manufacturer's website. Just to be safe, upsized to 750w.
I recently purchased a Gigabyte B450m DS3H motherboard and AMD Ryzen 5 2600 to upgrade from my 2015 pre-built. Upon install, my computer turned on fine. I used the packaged BIOS driver disk to install the drivers, during which a computer restart was required. The computer shut down, but did not...