Make sure the helmet only work under tungsten bulb or in the welding . It will not work under sunshine or flashing camera or led light。 . If there’s a test button, please check if it works. (Note: Make sure it is in welding mode) 3. Adjust the sensitivity to the max, adjust the delays and shades. 4. Test the battery if it is dead. (Normally, it’s 3V). 5. Make sure the battery is put inside correctly.  6. Make sure there‘s no dust on the sensors or the len.