I've had this happen. The center post one the end that screws into the battery should be slightly protruded from the outer ring. Otherwise, when the atomizer is screwed tightly into the battery it won't make center contact. Do this with a straightened paper clip with a tiny hook formed on the end. Stick it into the hole, being careful not to contact the heater coil. Pull it out just a little and try it again. The center post is suspended in a ring of insulating silicone material.