How sensitive is your L2D to being bumped?

I preordered a L2D-CE back when they first hit the market a few months ago. I really like it but I have to say I am rather disappointed in its duty as a work light. I have been EDCing it and really have been pleased and confident with it in that duty.



I'm disappointed in it as a work light because I have found that when I'm using it in high or medium mode all it takes is a light bump against some component on the piece of equipment I'm working on and I find myself squinting because my light has unexpectedly gone into low…Lately I have found that all it takes is a good jostle to send it back to low.



Did I just get a bum light? I am a pretty avid lurker around here at CPF and I haven't seen any mention of this issue. This is a huge issue for me. I have been a Fenix fan since I first laid my hands on the L2T. If this is a characteristic of digital regulative circuitry I will have to not consider a light of this nature for work duty.



Hopefully I just got a bum light and I can send it back to 4sevens for an exchange.

Is it a bump on the head that usually causes it to change modes? If so you might need to clean the threads. For a bump to cause it to change modes it would have to lose power for a moment. It could also be a bum switch. Either way I can smack mine aroudn pretty good and it stays in whatever mode I have it set on.

Mine does the same thing. When bumped or jostled on medium or high it goes into low. I tried a complete cleaning and it didn't make any difference. I think it's the switch.

My initial thinking is incorrect. If it is a momentary power loss the light should go into the next mode(med to high, high to SOS etc) not back to low.
Exactly how hard of a bump are we talking here?

Try padding the tube by using some folded aluminum foil at the rear or between the cells, so the batteries will not have room to move. With my L1D tube, this does not happen, but I can slam the light into my palm on high with the L2D tube and it will go to low.

edit: wait, it can't be the switch, gotta the head...unless something weird is going on (is the switch debounced?)

More testing...no, it's gotta be the switch. It won't go to SOS mode, but I can do turbo->strobe and med->high by banging it.

My initial thinking is incorrect. If it is a momentary power loss the light should go into the next mode(med to high, high to SOS etc) not back to low.
Exactly how hard of a bump are we talking here?

Click to expand...

Not that hard. Setting it down on a desk in candle mode, hitting it against my palm(moderate bump). If done easily it doesn't happen.

Added: Unscrew the head further then try it.



Wow that's way too sensitive. It sounds like something wierd going on there. Maybe something loose in the head? I don't know.

What he said. I still have marks showing from trying to get it mine to do it, here. I have to hit it straight up or down along the length, and hard.

Man oh man, my L2D has been working flawlessly for the last 5 weeks since I received it. I've used it every day.

Its sitting right here beside me, but I sure don't want to start intentionally smacking it around to see if it changes modes. I haven't even dropped it yet!

I drop mine all the time - no flickering or mode switches. I'm using big fat Duracell 2650's though.

Hmmmm....... I've been using mine daily.....er...... nightly for the past 2 weeks, no problems, in fact I've really enjoyed that fact that it lives up to what everybody was saying about it.

I just tried a few light-to-medium whacks on the side....nothing, however, I was able to get it to finally change from high to low when putting it down on a table top, in candle mode, but that had to be a pretty good whack, much harder than I would ever normally do. Funny that it didn't go from high to SOS, but went from high to low. Hmmmm.

It certainly doesn't present a problem for me, I don't think I would ever have noticed that unless I was trying to do it, but it sounds like yours might be needing much less of a jostle to change, so, you might want to check with your dealer.

For the short time I had mine while before sending it for a replacement, there weren't any issues about bumping.

Well, I think it's pretty clear that either the OP and SteveL have bum units, or very short AA batteries, and y'all should see if you can get them replaced, I think, unless you are just using short batteries by some chance. On that unlikely chance, my cells, which seem to do fine, measure 51x14mm, including nipple(maybe even a touch over 14mm).

I wasn't kidding when I said I still had marks on my hand after nearly 10 minutes from trying it a second time! If you drop it on a floor and it has a problem, that's why some lights have special parts to handle this (foam, very stiff springs). But anything short of that kind of fall, and something else is surely up.

I experienced the same problem if you don't loosen the head enough. If you don't back the head off at least 1/8 to 1/4 turn, even a slight sideway push on the head will cause it to go into turbo then back to normal. When it flicker back to normal it will always start from low. The light actually switched mode from med/hi to turbo then back to low. But you will only noticed it going from med/hi directly to low. How much you have to back off will depend on how much slops the threads have. On my light backing it off 1/8 of a turn from turbo seems to do the trick.

I have had no problems with mine so far, the tail switch can be a bit sensitive if knocked

Originally posted by Jadepp

I experienced the same problem if you don't loosen the head enough. If you don't back the head off at least 1/8 to 1/4 turn, even a slight sideway push on the head will cause it to go into turbo then back to normal. When it flicker back to normal it will always start from low. The light actually switched mode from med/hi to turbo then back to low. But you will only noticed it going from med/hi directly to low. How much you have to back off will depend on how much slops the threads have. On my light backing it off 1/8 of a turn from turbo seems to do the trick.

Click to expand...

I think you may have hit the nail on the head here. My threads do have a bit of slop in them. I will test this later and post my results.

I have dropped mine from 8 feet to a carpeted floor several times just to test it.
It works just fine after every drop with no ill effects at all.
This is a great little torch and continues to grow on me every day.:rock:

Yep, I had the same issue, backed off the head as suggested, problem fixed!

Thanks for the suggestion Jadepp. I loosened the head more and now it takes a pretty significant shock to produce the same effect. Now come Monday I'll have to try it in the field and hopefully I can use it with out any more issues. Thanks for all the suggestions fellow CPFers!

I use my L2D as a bike light, fair amount of vibration and occasional bump.

The mode changes from flashing to turbo farily frequently, but never from turbo back to flashing. Or if you give it a whack from the back (not hitting the switch) it'll mode change.

Hope this can be eliminated. Already tried the head loosening, still happens. Any definitive fix?