Didn't wait until next days. Followed your workaround..
Removed battery and hold down power button for a minute. 4GB Micro SD Card with Adapter formatted as primary FAT32 with 32KB, MBR, run test until end, card is ok, no errors, deleted files from test, copied CFW starter kit to the card, booted several times, no luck. Still the same.
Try a different micro-to-standard SD adapter. My guess is that either your 3DS cannot communicate with that SD card because of that adapter or its SD card slot reader is broken.
Edit - Did you make sure to unpack the starter kit? Just checking as *.7z by itself won't do anything.
Last edited by TurdPooCharger,