Which brand and type of battery are you using? If easier, you can send us a picture. We also recommend testing 2x CR123A batteries to eliminate the battery as an issue.
Can you check the images and follow the steps below to test the light? It might resolve the issue right away.
1) Unscrew the light into three separate pieces - the head, body tube, and tail cap. (Note. in recent batches, the head unit is glued down to the body tube. If that's the case, do not force it and skip this step)
2) Use a piece of clean cloth to wipe the contact inside the head, and wipe both ends of the battery. Sometimes grease or dirt from hands or light gets on the light or the battery which prevents the light from working properly.
3) Install the head on the body tube and fully tighten it.
4) Install the battery with the button top (positive end) towards the head of the light.
5) Install the tail cap, and fully tighten it. Most issues are caused by looseness in either the head or tail cap.
6) Press and hold down the switch button while looking straight at the LED. The light defaults to the lowest setting, which can be hard to detect in a bright room.
Does the light work now?
