If the lights are all just solid, that suggests to me that you aren't getting a clean boot, so the console settings aren't relevant yet. In my case, with a clean boot, my HDD lights flash intermittently while booting, then go solid. The top system LED flashes intermittently after a good boot. How did you burn the image onto the SD card? I used Balena Etcher on a Sandisk card and got a good boot on the first try. I'd recommend re-burning the image, then reinsert the card, making sure to get a solid "click" when it seats. If it boots and you see the system LED flashing, then the console is actually optional - if you check your router settings you should be able to see which DHCP address was assigned to the device (it will have hostname "helios64", and then you can SSH directly to the device using "root" and "1234" as the default login info.