Just wanted to chip in to say this was the solution in my case. I wasn't even getting any logos. The issue was that after installing the mod, I added an ExFAT SD card. This switch had never had any SD card before the mod.
I'm getting into the 3DS homebrew development scene with this simple tool. Just drag as many cia and/or 3dsx files as you want into the same folder as this tool, run it, and it will host the files on a temporary local web server and generates QR codes that you can scan with FBI Remote Install...