DS top screen backlight will not turn on when a game is in

As far as i know ds lites will play ds games (in the back) and gameboy advance games (in the front) the gameboy advance slot usually has a cover on it you pull off.....If its not working all the time buy some compressed air in a can and blow out where the games go....hope this helps.

the slot in the back is for individually bought cartridge games. the one on the top is for nintendo ds games, and the bottom slot is for gameboy advance games.

If you need to insert a game made for the DS you'll find the slot by holding the unit so that both screens face your, then looking at the opposite side, on the thin edge, or the part that has the buttons.
If you need to insert a game made for the Gameboy Advance you'll find the slot facing you if you hold it with both screens facing you. A removable cover is in place to protect the system when this slot is not in use.
DS, and DS Lite devices have both slots. The newer DSi systems and the 3DS do not have an options to work with the Gamebody Advance cartridges.

No, you dont need to buy a ds card, ds card is another word for a ds game, also game pak is also another word for a game boy advance game. so don't worry about it and enjoy your ds : )

well if thats the problematic case,

if it says no game inserted and theres a game in the slot,
this reallt worked
1 turn the ds off
2 take out the ds game
3 turn on the ds(remeber the game is out of the slot)
4 turn off the ds
5 carefully blow on the ds game all around
6 then blow in the slot were the ds game goes.
7 now put the ds game back into the slot.
8 now finaly trun on the ds and it should say theres a game in the slot

is it definitely "any" game? Reason is that a lot of games are now suffering from flat batteries, the symptom of which is what you're saying, corrupt save data.

The only solution is to change the battery if thats the case.

http://forums.console-world.co.uk/forums/index.php?topic=2.0

You shouldn't need anything other than a working DS and the game. If it isn't working, then try it on someone else's DS to make sure it's not the game, if it's not, are you having problems with your DS and the top screen?

Yes, GBA games will play on the DS. And I'm not sure if it matters to you, but you can also pick whether it plays on the top or bottom (touch) screen

my DS wont turn on.

she has to put the cartrigde for ds in the bottom slot the gameboy games go in the top slot