DS not recognizing my ds-x

Up until now my ds worked fine with the ds-x card. Today however, my ds will not recognize the the card >:( . It just shows up as a blank box .The first thing I did was check my ds to make sure it was still working by using a regular game. I tested it and the ds read the game just fine .So then I decided to test my card to see if it was the problem so I plugged it into my pc. The LED lights came on and I can access all the files just fine. In fact the LED lights come on when I put the card in my ds >.<.I'm using a DS lite
a 16 gb (2 gb) ds -xThe last game I added was Professor Layton and the Curious Villiage (which worked fine and I played it yesterday
)Before that I added tetris =xI'm not sure what's wrong with it. I treat my toys well >.<; so I don't think either of the two things are damaged. Any help would be greatly appreciated.

Try replaceing your files, Mabe one file got deleted by mastake

:( Didn't work.

So the card doesn't boot up, right? It's happened to me a few times too, especially with older and more used cards. One way is to clean the contacts on the chip, but do that at your own risk... My dad cleaned mine with (I think) isopropyl alcohol, and it worked fine after.

The card isn't old though. I got it December 20th.

I think he means backup your games and saves , format your microsd , replace your kernal and games & saves

There's currently nothing on the cart except the original files it came with. It's still not working :(