R4 isn't starting up on my NDS....

Today my brother started up our NDS with the R4 cartridge and chip in it and all he got was a frozen screen with the words 'Loading....' on it.
What should I do to fix this problem?

The easy fix:Take out the R4 and blow on the card and your DS slot, if you have one of those air blower cans used to clean electronics use that.Next make sure the micro sd is seated correctly, try pushing getting the sd out and then firmly putting it back in.Then put the R4 back in the DS and start it up.If that doesn't work, hook up the micro sd card up to your computer and quick format it, and re-install the correct firmware plus games onto it.Hope this helps.

I'll try that out thanks :)