The most common cause of light dimming and subsequent features lose is due to drained batteries. As the batteries are consumed they supply less and less power to the light. To compensate for this issue your light will step down the brightness of the primary white LED from the highest setting, to medium and then low. When battery drain becomes too low features on your light will turn off in order to supply the power to the primary white LED. To restore your light to full functionality please replace your batteries.