3DS booting slower than usual

3DS booting and switching between apps slower than before. Opened it up and it was just a black screen. I was able to remove the SD and reboot, reboot with the SD back into Luma etc but it is slow booting and swapping still. Not sure if it is the SD card or something else. Is there a health check tool or something that I can run to determine if/where there might be a problem.