Need Help with a NiteCore D20

I've been reading the forums for a while, but just decided to participate. Thanks for all your posts.


Now for the issue:

I purchased a NiteCore Smart PD D20 in October of 2009 from 4sevens. I'm having some trouble with the light.

Here's my problem: The light appears to be operating at about 50% of the expected output. I continued to use the light at the reduced output for a little while before I installed new batteries. After I installed new fresh batteries (the same standard Duracell AA's), the light remained at the same reduced output. I then tried two more sets of fresh batteries, but the light stayed at the reduced output level. All of the user interface functions still work as expected (ramping, double-click, click-hold, etc).

I contacted 4sevens (hoping they would help because it's still under warranty). They weren't much help. They told me, "We do not have an in-house remedy for you. Please contact Nitecore directly for repair/replacement."

I've contacted NiteCore directly and they want me to ship it back to China. I'm not really interested in paying for shipping (to and from China). That could turn out to be a pretty pricey endeavor.


Do any of you have any suggestions on how to fix this? I'm new to "high-end" flashlights, but I can follow directions.

Any help would be greatly appreciated.

Define expected output. There's always the slim chance that you're overestimating how bright it should be. I'm not questioning you but there's always the chance.

Sorry to hear you have a problem with your D20. I have had a few of these lights and they can pose problems from time to time. The brass ring and positive terminal at the back of the circuit board in the head does require regular cleaning. With the light off, if you tap the light against the palm of your hand and the light flickers on/off, then you have a dirty positive terminal.

If some piston commands are missed, you have a dirty brass ring. If you have checked the voltage of your cells and are sure they are fresh, and you have cleaned the terminals, then you may have an internal circuit problem.

No fix here for that, you will require a replacement pill. Normally, if a D20 board fails, it just does not turn on!! I have never heard of a D20 working but only to around 50% of normal output.

You may also have an emitter problem. Has the light been left on high unattended for an extended period? Has the tint of the emitter changed colour: turned blue for example?

Sorry I can't help you further.

James....

Try Eneloop.