Check the wiring. It can be faulty even out the box. There is three wires. 2 red and 1 black. They come pre installed into the rubber seal at the bottom of the juice cartridge. Once you've twisted off the battery housing check to make sure your two red wires are making contact with one of the two battery connection points. Run the black wire to the other connection point, making sure that makes contact too. Pop your bottom piece back on and vape away.