Make sure that the atomizer is making contact with the battery. The coil should be screwed all the way it and has to make contact with the bottom of the tank and then the tank has to make contact with the positive pin in the mod. I don't remember if this mod says "no atomizer" when it does not find the tank, but it just sounds like it's not making contact. You may need to pry up the center pin of the battery just a hair, or lower the positive pin of the tank. Alternately it could just be a bad coil.