Need more details.
'Doesn't work' is not clear enough. Let's try again:
- What device are you trying the card in?
- Which firmware is on the device (i.e. NDS 1.4.5 or .1.4E.. 3ds 9.9.1.-32.. )
- Is the card detected as a game at all when inserted in the device?
- What does it do when you try to start it?