I tried the 2 draw on a new harmonica this morning, a fire breath, and couldn't get anything. I know about the problems some have with 2 draw, but it hasn't been problematic for me. Could there just be something wrong with it? I took the cover plates off and the reed looked fine.
Gently plink the reed. Maybe that will free it up.
Are the reeds riveted on? Check to see if it's straight.
Look REAL close. Use a bright light and a magnifying glass. Maybe there's a piece of crud in it.
Another possibility I forgot to mention:
Improper gap.
If the gap looks different than the gaps of the reeds next to it, adjust it by bending it very gently and a little bit at a time until it looks like the others. (The gaps are wider at the low end of the harp and gradually get narrower toward the high end.)
It can be hard to play. From my own experience, its from drawing air in from the mouth, rather than the stomach... which is the way to play the instrument.