1. For testing purpose, remove the pocket clip from the light if it is installed.
2. Unscrew the tail cap and the head from the light. Basically break the light into three pieces: the LED head, the body tube, and the tail cap.
3. Use a piece of cloth to wipe clean the threads on both ends of the body tube.
4. Screw the LED head on the body tube and make sure it is fully tightened.
5. Install the battery. Put back the tail cap and make sure it is fully tightened as well. Most light issues are caused by a loose LED head or tail cap.
6. Plug the micro USB end of the cable into the light. Plug the other USB end to a USB port (e.g. a computer USB port) other than the AC power adapter. Under normal charging conditions, the blue power indicator light will illuminate steadily to notify users. When charging is complete, the MH10 will terminate the charging process automatically and the blue power indicator goes out.
7. Charge the light for 6 hours.