Contact DX. Usually they won't require that you send back the defective one, and maybe you'll get it before Christmas (unlikely, but you never know).

Have you checked all of them to see if any are fake: http://www.ndstt.com/en/anti_fake.html

Make sure you don't install the latest firmware (1.16) because there are reports that it can destroy certain fake DSTT's.

-Bri

 

The following post is from the "How to tell if your DX DSTT is a FAKE" thread, page 7:

The new legit cards have a chip on the back side of the PCB. Open the card up and check it against the NDSTT website's Anti-Fake page.

 

Dealextreme is very good about replacing faulty and/or fake flash carts, so I have no doubt that they'll replace it. However, whether you'll get the replacement by Christmas is another matter (as you know since you've ordered from them multiple times).

Still, if it's defective there's not much else you can do but get a new one. If you have to have it before Christmas, you could purchase one from another store like realhotstuff.com that ships faster.

-Bri

 

goes strait to ds health screen.