First please make sure you are ONLY using our bulb. The bulb is a special 12 volt LED and is not easy to find a replacement at your local hardware stores. Please see our PARTS page to make sure you are using the correct components.Secondly, make sure you are using our wall charger, also has to be a 12V charger that fits your battery pack.Finally, check to make sure the bulb and battery are securely seated in the socket and base or battery plug at the bottom of the lamp.Still having trouble... It might be time for a battery replacement if it is over 2-3 years old, or please feel free to reach out to us to help: support@modernlantern.com