Fenix SD11 Troubleshooting StepsUpdated 2 hours ago

Confirm that your batteries are good. Try using the battery in another device.

Confirm that the battery/batteries are inserted into the light facing the correct direction. The Positive (+) side should be toward the head (LED) of the flashlight.

Confirm that there is only one o-ring on the light. The o-ring that comes in the box is a spare. The light already has an o-ring on it when you first remove it from the box. If you put on the spare o-ring, please remove it as this will prevent the light from making a full connection with the batteries.

Lubricate the o-ring using a small amount of petroleum jelly on the end of a cotton swab.

After you have completed the above troubleshooting steps, if your light is still not working, visit our Warranty and Repair page to review the policy and submit a claim.