HELP!!!

Whipe the cartridge with a gentel, soft cloth. Then get a cotton bud/swab and very gently rub the inside of slot 1 on your DS. If this dosent work, contact the Nintendo support.

You may have damaged your DS cartridge somehow. However, this damage may or may not be visible. I have an Age of Empires game that no longer works, but there's nothing wrong with it physically.

Well, I am having the exact same problem...
---OPTION 1---
You need Baking soda, a toothbrush, water, and a water bottle cap.

First, put baking soda in the water bottle cap. Next, pour the water in the cap. It should fizzle. Next, get the toothbrush, and gently brush... it worked, but for a little time... it may damage the game, i don't recommend using this option.


---OPTION 2---
You don't need anything but your game.

First, you should be at the menu screen, where you say the game doesn't appear. Next, with your thumb, try to take out the game with your thumb. Do it with power. Pull it out like just like 1/4ths of a centimeter. Next, softly keep tapping it in very gently... it should appear. If it doesn't appear, just keep trying.

~If none of these options work, try this option... it has a certain chance for the game to work.


---OPTION 3---
You need alcohol, a cu-tip (the things you use to clean your ears for earwax), a tin cloth, and your game.

First, dip the cu-tip in the alcohol. Next, rub it on your game gently. Next, dry it with the cloth. Now, try putting it in your DS. It should work.


~If none of these options work, I am sorry to say, I can't help you. Check the Nintendo Support for more information in trying to put it in your game.
http://www.nintendo.com/consumer/index.jsp
~

Best of luck, from
kirbyman100.

Its either dirty in there, or you just need to keep putting it in and taking it out. It has nothing to do with mario kart my DS does that all the time. Try putting it in again and pushing harder when you put it in keep pushing for about 20 seconds then let go leave it in it should work when you turn it on. If you didn't understand a word I said I don't blame you. Maybe someone else could explain it better. I don't think you need to clean it unless it's all gunky in there. Just try putting it in, taking it and all of thee above.