I have tried to format everything once more, and followed the 3ds.hacks.guide frogminer guide.
Same problem. Following the instructions on JP Flipnote and getting:
Initializing FAT... good
Initializing NAND... good
Checking for A9LH...
A9LH detected! Brick avoided!
"link to webpage a9lh-to-b9s"
Press home to exit
I don't understand anything. Everything should be at the right place!
False alarms for a9lh are common because old tools don't correctly clean up after uninstalling a9lh. If you are COMPLETELY sure you don't really have a9lh installed, you can override the a9lh warning:
https://github.com/zoogie/b9sTool/blob/master/TROUBLESHOOTING.md (first one)
Keep in mind that if you DO have a9lh and you proceed, you will brick the system and you'll have to buy a flashcard to repair it.
So override at your own risk.
btw - a little trick to test for a9lh: Boot frogtool and select the middle BOOT ..... command.
If the system just hangs at a black screen for more than 30 secs, this 100% means you still have a9lh. If it boots a game or app, then you are
probably ok. As before, be cautious and override at your own risk.