D10 Problem?

Hi all,
I went to switch my D10 on today, and found that it only switches on about 50% of the time. I can twist the head to the point where it's tight, and it won't go on, then I untwist it, and re-tighten it, and it goes on. Same thing with the tail switch - I can push it fully in (with the head loose or tight, doesn't seem to make much difference in whether it works or not), and it will only sometimes activate the light.

I've done a bit of testing to see if I can feel whether it's a contact problem or not. I untwisted the head to the 'momentary on' position, and tried to activate the tail switch by pushing it in. I can push it in to the point where I can feel what I presume is the battery touching the terminal at the head of the light, and most of the time it goes on (probably 70% of the time). However, if I push it slowly, I can get to that point where I feel the contact, but the light doesn't come on. When that happens, it doesn't matter how far I push the piston in and increase the pressure on the battery, it still won't come on (which doesn't sound like a contact problem to me, but what do I know). In constant-on mode (head tightened), the light does the same thing, although the problem isn't as frequent.

The same thing happens when I try to switch it on 'normally' (i.e. not slowly activating the switch). Interestingly, it seems to get better the more I use it in a short time period, which would suggest a contact issue... but then I leave it and pick it up two hours later, and it's back to square one.

What happens with these lights when the battery wears down? I understand they're digitally regulated (I think?) So do they just refuse to come on if the battery is too dead to supply the necessary output for a given level? Or do they still work, and maintain the maximum brightness possible for as long as possible, then drop like a rock to minimum? What happens when it gets to minimum, and starts running out (3 lumens)? Does it keep going until there's nothing left, like an unregulated light?

I don't think there's a battery problem, because I can still crank it up to full power, and it looks to me like full brightness (and keeps going).

Any ideas? Sorry for my long-winded post.

Edit: I just realized the first paragraph makes it sound like I don't understand the UI of this light. I'm pretty confident that I do

What you describe in your first paragraph sounds like something I experienced with my first EX10. It had a sticky brass split ring that was most likely causing the problem. Is yours tilted, i.e. not seated quite right, when you remove the head? That's how mine often was. If you can't fix it by twisting the ring, lubing it, and opening up the gap a tiny bit, I'd consider sending it back.

About batteries and regulation, I'd look at selfbuilt's review for a definitive answer. Anecdotally, yesterday I noticed that my EX10 wasn't as bright as I thought it should be on max. It only took 2 seconds to ramp up to max from min. Turns out it was due to the battery being close to dead. When I put in a fresh battery, my max mode was back to its normal blinding brightness. So no, my light didn't just refuse to light up when its battery started to run out of juice. It just refused to blind me on max.

Change the battery. Mine only worked about 1/2 the time...until I put a fresh battery in it.

The old and new versions of D10 and EX10 have their own bugs yet.
But I guess your dealer or nitecore will exchange yours with the new one if there is a problem.

You may want to figure out whether yours are old or new version, below.


https://www.candlepowerforums.com/threads/201948&highlight=nitecore

Thanks guys.

I cleaned the brass ring off a bit with a needle, and wiped off the top (contact) edge of the piston, and it seems to work a lot better now. I wonder if some grease from the piston got onto the top edge, and was insulating the contact between the edge and the brass ring, or something.

I have also discovered that it depends a lot on how quickly I push the switch - if I rapidly push it after it failed to come on, it won't come on no matter how many times I push the switch. If I leave it for a couple of seconds, it pretty much always comes on the next time I push it. I wonder if this is a UI thing - it's like it's waiting for more input or something, like a double-click.... but then I would have thought the light would have come on on low mode anyway, which it doesn't appear to be doing.

The light is one of the new models, according to those photos - it has the 5 big black IC's/chips on it, and none of the smaller ones.

Anyway, thanks again for the info, and I'll see what happens over the next few days.

Getting the piston and the brass ring travel moving smoothly is paramount to reliable operation.

Hmm, well I think both are moving smoothly. I still don't know what caused that blip in reliability, but it seems to be back to about 99% now. It hardly misfires at all. I would still trust the light (even when it was only working 70% of the time), because it doesn't feel like the kind of problem where you wouldn't be able to activate it at all and it would get worse, just the kind of thing where it might take two pushes to get it to come on instead of one.

I think the cleaning of the ring and the edge of the piston must have improved the situation. I might look into getting some of that deoxit stuff that everyone seems to rave about here, looks like it might make it even better. Does anyone know if I can use copper cleaner instead? Brass has a pretty significant copper content, but I don't know whether the alloy will behave the same way. I have some stuff on hand that totally strips the oxidation off the bottom of a frypan without even rubbing it.

I'm not sure what's in the copper cleaner but I wouldn't put it on/in my flashlights. Especially in a situation like the D10. You need that brass ring to move freely and there's no telling that the cleaner might eventually gum up the works. Or get into somewhere where it's not suppose to. DeoxIt is recommended for a reason. Not only does it clean the oxidation off the surfaces, but it also remains liquefied and acts as a lubricant. It's almost as if it was made for the NiteCore PD's.


And in regards to the piston, when I say smoothly, I mean easily. The button needs to snap back quickly for proper operation. I don't use DeoxIt here but I'm sure it works just fine. I use NanoLube in this situation.

Update:
Last night, I couldn't turn the light on for about 5 minutes.
When I finally got it to come back on, I turned it off by un-twisting it, and then I couldn't get it to come back on again, using either twisting or the switch. I must have pushed the switch 100 times while the head was both twisted tight and loose, and nothing.... I tried turning the battery around (not reversing polarity, just spinning it) and it didn't seem to help.

I did finally get it to come back on after leaving it alone for around 10-15 mins, so I tried switching it off by untwisting it again, to see if I could repeat the problem. I think it came back on again when I re-tightened it, so then I untightened it and again re-tightened it, and it failed to come on. And it wasn't just accidentally in 'off' mode either, because when I pushed the button, it wouldn't come on. Repeated button pushings did nothing.

I picked it up this morning after leaving it overnight, and it works again. I'm starting to think there may be a problem with the actual circuitry in the light, rather than a contact issue.

I think I'm going to send this one back, and get a Fenix instead. Does the L1D CE have a finicky switch in the head to switch between turbo and normal modes? Also, is the PWM it uses invisible like the Nitecore, or a lower frequency?
I'm also looking at the Olight T15, or the T25. Anyone have any opinions on which is better between the Olights or the Fenixes?

Oh, and once again, thanks to everyone who has replied, you're very helpful

What kind of batteries are you using?

I'm using normal, cheap Energizer AA primaries (alkalines). I put a brand new battery in last night though, and the problem repeated itself.
Also, when I switch the light to full power when it's on, it still manages to output at full power (to my eyes, at least) for the entire 10-15 seconds I leave it at that level to test it... wouldn't that indicate that there's still at least sufficient juice left in the battery to make the light run?

Also, @ Lite Me,
The piston seems to be pretty free and springs back quickly - it had a nice action right out of the box.

E=MC2 said:

Update:
I think I'm going to send this one back, and get a Fenix instead. Does the L1D CE have a finicky switch in the head to switch between turbo and normal modes? Also, is the PWM it uses invisible like the Nitecore, or a lower frequency?

Click to expand...

Finicky switch: sometimes, about 1/3 of my Fenixes have become a bit finicky over time.
PWM: Nope, current regulated.

E=MC2 said:

I'm using normal, cheap Energizer AA primaries (alkalines). I put a brand new battery in last night though, and the problem repeated itself.
Also, when I switch the light to full power when it's on, it still manages to output at full power (to my eyes, at least) for the entire 10-15 seconds I leave it at that level to test it... wouldn't that indicate that there's still at least sufficient juice left in the battery to make the light run?

Also, @ Lite Me,
The piston seems to be pretty free and springs back quickly - it had a nice action right out of the box.

Click to expand...

FWIW I think your problem could be the cheap AA batteries. They simply don't provide enough juice to sufficiently power most modern LED lights. They may drain quickly, and when you pick them up, you get inconsistent voltage. Sometimes they rest, and recover for a very brief period of time, other times they don't.

I use nimh batteries like the Sanyo Eneloops in my D10s and all my other AA and AAA flashlights (except the Fenix E0 and E01 which are very low power), and I have not had a single power problem.

I would suggest that your problem is related to you using these alkaline AA batteries which simply are not consistent enough to provide the required voltage to the modern LED flashlights.

I wouldn't spend a lot of money buying nice modern lights, and feed them decades old technology (alkaline batteries) except for emergencies where that's my only choice.

Try Eneloops or Lithium AAs and see if there is a similar problem. And report back and let us know. I would suspect most of your problems would go away. From your posts it jumped at me that it seemed like finicky batteries you were using that's why I asked about what you were using.

If the light is truly defective even after you test it with other types of batteries (other than alkaline), simply swap it with another D10 from 4sevens and you should be good to go. This is why I buy my stuff from 4sevens - for the peace of mind that he will back his products when problems arise.

I had a similar problem I traced to battery length... using AW 14500 my shortest battery is 2.03" long and functions but the longer is around 2.05" and inhibits switch travel to the point it does not function. Most commercial AA's are right at or under 2.00" and seem fine, as are also my Eneloops.
This is my first run at using AW's in things and I am liking them very much, outside of this minor blip. My long 14500 will now just be relegated to a Fenix.

I'd get it replaced if possible. Good lights are too expensive to be unreliable or finicky.

carrot said:

Finicky switch: sometimes, about 1/3 of my Fenixes have become a bit finicky over time.
PWM: Nope, current regulated.

Click to expand...

Hmm, that doesn't exactly sound like a great solution either then :sigh: Thanks for the info.

LED-holic said:

FWIW I think your problem could be the cheap AA batteries. They simply don't provide enough juice to sufficiently power most modern LED lights. They may drain quickly, and when you pick them up, you get inconsistent voltage. Sometimes they rest, and recover for a very brief period of time, other times they don't.

Click to expand...

That's a very good point, and.... I think you just solved my problem! (I think - further field testing required ).

When I switched the light off by twisting it, and it failed to come back on again, I had it on full power. I'm now wondering if it fails to come back on in that case because the battery voltage is too low to kick the light back on in 'high' mode, so it just doesn't come back on at all (I guess there's no programming in the circuit to tell it to reduce the output to minimum if the switch is depressed and there's insufficient voltage to run it on high)?

I got the light to switch on, set it to 'high' mode, and ran it for 5 minutes on the old battery, just to depress the voltage a bit more. Then, I untightened the head to switch it off. I then retightened the head, and voila, no light, after repeated attempts to switch it on! So I put the new battery in, and it worked perfectly every time.
I think you may have just completely dispelled any questions I had about the reliability of this light (again, pending further testing....)

If this proves to be the answer, I still consider this to be a bit of a flaw in the design of the system, although I guess this applies to all programmable/non-direct-drive lights? I would have preferred to be able to switch the light on with a low battery, even if the output looked like it came from a toy light out of a cereal box. I'll get some Eneloops and see how it goes.

I guess I just won't switch the light off from 'high' from now on, just in case.

(Did LED-holic and I just discover a new and un-catalogued bug in the light)?

Thanks again to everyone for your help.

Any Cal. said:

Change the battery. Mine only worked about 1/2 the time...until I put a fresh battery in it.

Click to expand...

And I just noticed this reply from a few days ago - sorry I didn't pay attention to it, but thanks for the info :twothumbs

E=MC2 said:

...

That's a very good point, and.... I think you just solved my problem! (I think - further field testing required ).

When I switched the light off by twisting it, and it failed to come back on again, I had it on full power. I'm now wondering if it fails to come back on in that case because the battery voltage is too low to kick the light back on in 'high' mode, so it just doesn't come back on at all (I guess there's no programming in the circuit to tell it to reduce the output to minimum if the switch is depressed and there's insufficient voltage to run it on high)?

I got the light to switch on, set it to 'high' mode, and ran it for 5 minutes on the old battery, just to depress the voltage a bit more. Then, I untightened the head to switch it off. I then retightened the head, and voila, no light, after repeated attempts to switch it on! So I put the new battery in, and it worked perfectly every time.
I think you may have just completely dispelled any questions I had about the reliability of this light (again, pending further testing....)

If this proves to be the answer, I still consider this to be a bit of a flaw in the design of the system, although I guess this applies to all programmable/non-direct-drive lights? I would have preferred to be able to switch the light on with a low battery, even if the output looked like it came from a toy light out of a cereal box. I'll get some Eneloops and see how it goes.

I guess I just won't switch the light off from 'high' from now on, just in case.

(Did LED-holic and I just discover a new and un-catalogued bug in the light)?

Thanks again to everyone for your help.

Click to expand...

Thanks for the additional information. I guess this could be a problem depending on how one uses the light. If one runs the light exclusively on alkalines, and don't have spare fresh batteries available, it could be an issue.

This is why I always carry fresh, spare batteries. I have my D10 in one pocket, and my L1D always with a fresh Eneloop in another pocket. That way if the battery dims on the D10, I can swap out the battery quickly. The L1D is there as a battery holder, and also in case I break the D10 in some freak accident. So I have double back up.

Let us know how the Eneloops work out for you. I suspect they will work far better for you.

With the Eneloops there is no concern about turning off the light in "high". And guilt free lumens truly is a reality with these batteries.

brandx said:

I had a similar problem I traced to battery length... using AW 14500 my shortest battery is 2.03" long and functions but the longer is around 2.05" and inhibits switch travel to the point it does not function. Most commercial AA's are right at or under 2.00" and seem fine, as are also my Eneloops.
This is my first run at using AW's in things and I am liking them very much, outside of this minor blip. My long 14500 will now just be relegated to a Fenix.

Click to expand...

Good to know. Thanks. I think I'm going to stick to NiMH's, though.

Jaygnar said:

I'd get it replaced if possible. Good lights are too expensive to be unreliable or finicky.

Click to expand...

I was thinking exactly the same thing. If this turns out to be a battery issue though, which I think it is now, then I'll be happy again. The thing is, I really like everything about this light, from the build quality to the action on the PD, to the beam pattern, anodizing, etc. so if it's a battery problem, I can live with the fact that it won't be optimal on alkalines, and just use them as a last resort. Here's hoping.