What's wrong with my LED flashlight

[Dave Lehnert]

I have a 3, D cell LED flashlight.
I noticed when I turn the flashlight off the LEDs are still glowing but very dim. I can remove the batteries and the LED's go completely out. Reinstall batteries and they will glow dim again. Push switch on and it works as should.
I did a quick search on line and see the same question asked but no real answers.
Seems like if the switch was bad it would not work at all.

[Ken Fitzgerald]

It sounds like the switch in the "Off" position isn't open but rather resistive allowing some current flow to cause the LEDs to glow dimly.

In theory, you should be able to remove the batteries, using a multi-meter in the resistance mode and measure an open across the switch when it's in the "Off" position and a short when it is in the "On" position.

[Tom Stenzel]

The switch is passing a small amount of current when it's open. Could water have gotten into the switch ? Did a set of batteries leak and the light cleaned out- or not cleaned? If the switch has one of those rubber covers on it try removing it, see if it's wet inside. Or leave it disassembled for awhile to see if letting it dry out helps.
-Tom

[Dave Lehnert]

Thanks for the info.

[william watts]

Flashlights I have seen have the the switch in the negitve side of the lamp. The switch , when on, connects the lamp to the case of the flashlight. A current leakage path to the case before the switch, but after the lamp, could cause this problem, as well the switch. Maybe a spot of corrosion?

[David L Morse]

If it's a high quality flashlight it probably includes a LED driver circuit which is a current regulating switching power supply. On some of these the power switch doesn't actually switch the battery but instead activates an input to the controller chip, like the front panel power switch on a PC or a lot of other electronics. My switching power supply knowledge is about twenty years out of date so I really am not familiar with all the LED driver topologies but it's possible that there's one that supplies standby current to the controller through the LED load. This would account for a possibly very dim glow when off.

[Bill Orbine]

I wonder if you replaced the bulb in the flashlight........ as if the original bulb was an incandescent bulb?

[Jerome Stanek]

Contact CS and see if this is normal

[Dave Lehnert]

Not high end product at all but Looks and feels very well built. The light it give out is GREAT!