I'm no specialist in this kind of stuff, but I'm having the same issue. It could be any of these possibilities...
How long have you owned the device? They aren't products of Nintendo (so I hear), so they aren't as strong as you may think; the golden-hued part on the insertable end wears down as you remove, insert, and transport it in a cramped place.
Have you let someone borrow it? They may have dropped it somewhere, but the real damage is probably inside the device, rather than on the outside. (if no one borrowed it, then maybe someone else with an AR visited you and got them mixed up)
Does it not work on a few games, or all of them? Nintendo made the AR makers stop putting cheats on Pokemon games (the newer ones like Platinum). On the case of the AR that you got it in, it should say which Pokemon game cheats it has.
Is it visibly dirty? Cleaning may work in some cases, but don't overdo it; it may wear down the golden part even more than it is already.
If this helped at all, I'm glad I could help out. If it didn't, the like I said; I'm no expert at this stuff. If you've tried everything, I suppose the only option left is to buy another one.
Because the action replay makers have not made cheats for it or you haven't updated your action replay.
Well it depends if you buy an action replay FOR ds, but if you buy one for dsi, it wont work
you probably need to udate your action replay for the code to work.
It wont work because you system software is or is over 6.30. The action replay people are trying to work out a way for it to work.
there is a master code cheat to use the cheats in the action replay with out it the codes wont work
a. you need to update your action replay b.if you got it in a black case its American so it wont work anyway.
they give virusi's to your ds
shut the ds off put action replay in ds. turn on press action replay. take action replay out finally put ds game in and press on the star
apparently no unless you have a action replay but DO NOT use it it destroys game and action replay wont work at all
Unless you've rested you action replay or put in the code id and game code
you need a action replay for this otherise it wont work at all
Yes but there wont be any codes for it!