Well you did something for it to boot into a black screen, by default the Emunand take a copy of your Sysnand and use that as NAND,
I mean if you had SX OS emunand you can do what The Real Jdbye said. I have no experience with using Kefir so can't help you with that.
I tried converting SXOS emunand with Hekate but it corrupted it (good thing I backed up my saves), get this error - https://gbatemp.net/threads/issues-getting-atmosphere-to-run.587676/#post-9456489
So I have to start from scratch, which is what I am trying to do. I do not want to use Kefir, its the only thing out of everything Ive tried that works though. I want to just run plain Atmosphere.
I followed the steps for setting it up. From scratch. Formatting the SD Card and everything. But after the logo it leads to black screen.
I dont need help with Kefir, I need help with getting standard ole atmosphere to work. I have nothing to preserve. This is a clean slate. My Sysnand works, my Emunand is clearly find too if Kefir can boot into it. Its somehting with the atmosphere folder which I pulled from github that the issue is. Some setting somewhere, or file.