Yeah what I did was put the update file on my husbands working sd and flash cart, put it in his ds and ran the update file. Then I switched it for mine with my original sd card and hit a for the update but then it gets stuck on erasing device.

Hi, I have the same problem when I run the update it said check card fail. Is this possible that muy card is not fixable? I made a failed update and now it does not work1 - Put a working cart with the update file for the broken one in the DS.
2 - Start it up, start the upgrade file.
3 - Take the working cart out, put the broken one in without turning the DS off.
4 - Tell it to do the update.