# Surefire E2 Problem



## Monkey of Death (Feb 1, 2010)

Hi All!
I'm having a weird issue with my Surefire E2 and hope you all might have some ideas. I did a search and read several posts, but didn't find anything relevant, so I hope I'm not asking something already covered.

The problem:
My Surefire E2 (a very early, original E2), just stopped working. It was on and suddenly went dark. No dimming. Just out. I figured that the sudden outage meant a blown bulb, but I checked the batteries first, since I had spares. It was not the batteries (I even checked the voltage of the ones in the unit and they were fine). So, I ordered a new bulb. But decided to upgrade in the process so I ordered a LumensFactory EO-E2R bulb and 2) AW RCR123 batteries. Got them, checked the voltage on the batteries (good), dropped them in and... nothing. Without thinking, I started to put the old bulb back in and it lit up, for a split second before the higher voltage burnt it out (whoops..., but I thought it was already burned out).

Now it gets weird. 
If the tailcap is screwed down (on-position) and I set the new bulb assembly gently in place (just the bulb, not screwing the head on), the new bulb DOES light up. But as soon as you push down and compress the spring, like what would happen when you screwed down the head unit, it goes out. So the bulb is good, apparently. I got my wife's E1 and swapped the tailcap. Mine works on hers, but her's doesn't do anything on mine. Same thing with the head unit. So, it appears as if my head unit, tail cap, bulb and batteries are all good. That leaves the tube itself?!? And why does it work when the bulb is placed gently in place, but not when screwed down? Also keep in mind that this issue started with the factory bulb and batteries, NOT when I changed.

As an aside, when I bought this unit new in '01, I bought one for a friend as well. I told him about my problem and he replied that his had stopped working in pretty much the exact same way. 

So, any ideas, suggestions, tricks or mystic voodoo chants to work this out? Or do I just need to send it back to Surefire? I love this little light (obviously since I've had it for 9 years!). Any help is greatly appreciated! :thumbsup:


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## DUQ (Feb 1, 2010)

Did you try shorting the battery to the tube with a wire? This trick bypass's the switch to make sure everything else works. Also; some older versions of switches may not work on newer lights.


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## Monkey of Death (Feb 1, 2010)

DUQ said:


> Did you try shorting the battery to the tube with a wire? This trick bypass's the switch to make sure everything else works. Also; some older versions of switches may not work on newer lights.



Thanks for the reply!

I did try shorting it. The lamp didn't light, but I did get a few small sparks when the wire touched the tube. That seems unusual to me. Does that mean anything to you?

And the switches _should_ be the same since I bought the E1 and E2 around the same time (when they first came out). In any case, mine works on hers and nothing is working on mine!


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## ampdude (Feb 1, 2010)

It's not unusual to get a small spark when doing what you mentioned. I get them all the time when checking current. As to what the problem with the E2 is, I haven't encountered anything like you describe and I've had dozens of older E2's. My first Surefire was an E2 purchased around 99' or 00' and sometimes the light would be working and then would fail to turn back on when the battery was sufficiently weak. They don't always do that, but that is normal behavior for lithium primary cells sometimes. If you send the light to Surefire, you might not get the same light back. So if you are attached to it, I would not send it in for service work.


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## Monkey of Death (Feb 1, 2010)

ampdude said:


> If you send the light to Surefire, you might not get the same light back. So if you are attached to it, I would not send it in for service work.



That's what I was afraid of and why I came here first! It's not that I dislike the newer models, I just really like the simple design of mine. Of course, which design I prefer doesn't matter much if I can't get it to work


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## ampdude (Feb 1, 2010)

Yea, as in not getting the same light back, I meant they might just send a new one out instead of your old one back fixed. I didn't mean to imply that they don't keep track of whose light is whose. There are some things I dislike about the current models. I don't like the current round body, I don't think it has enough knurling and it is kind of ugly. Also, I wish the Z57 clicky was a little more robust for high current lamps. The twisty doesn't have any problems with higher current lamps. The older lexan bezels of the original E2's might melt under the heat of an IMR lamp though. By the way, if you're using incan lamps in that E2, I recommend the IMR16340 batteries over the RCR123A's. Your bulb will run brighter and you'll have better runtime. You have an older body, so there shouldn't be any fit issues with the RCR123A cells, but some of the newer E-series bodies made in the past couple of years will not accept the RCR123A cells as they are larger in diameter than the CR123A primary lithium cells.


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## jaundice (Feb 2, 2010)

Since you know that it sort of works, and that the batteries and lamp definitely work. I think you have a connection issue between one or more of the four parts (head, lamp, body, and tailcap). My guess is that corrosion has built up on on the bare aluminum electrical connections. I'd try rubbing a pencil eraser across those parts, which are at each end of the body tube and in the tailcap, and see if this helps. There are commercial chemical products that do the same thing.

Good luck!


-John


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## Monkey of Death (Feb 2, 2010)

jaundice said:


> I think you have a connection issue between one or more of the four parts (head, lamp, body, and tailcap). My guess is that corrosion has built up on on the bare aluminum electrical connections. I'd try rubbing a pencil eraser across those parts, which are at each end of the body tube and in the tailcap, and see if this helps.
> 
> -John



Thanks for the suggestion!
I had previously cleaned everything with alcohol, but after your suggestion I decided to give it another go. I also lightly rubbed the connections with some very, very fine sandpaper, just to make sure there wasn't anything stopping the connection. And... nada. No difference whatsoever. 

Again, as far as electrical connection goes, if I screw the tailcap down into the 'on' position and remove the lamp from the head and lightly place the lamp on the tube, it works. As soon as I press it down so it would 'set' on the top of the tube (this compresses the spring at the base, under the batteries), the lamp goes out. So there's a connection when the spring is 'at rest', but not 'under load'. And when you screw down the head, it compresses the spring and we're back to no light.

Weirdest thing I've ever seen....


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## Justin Case (Feb 2, 2010)

What tailcap do you have? This is what I have for my old E2:

Complete Z52 twisty tailcap, top. Tailcap shell and rubber button, bottom left. Tailcap plunger switch (with spring), bottom right.






Tailcap plunger switch with spring, side view





I would check the condition of your rubber button. It sounds like pressure from the top causes the plunger to push through the rubber button, which should hold the plunger in place. If the plunger gets pushed out the tube, then the wide flange can lose electrical contact with the exposed end of the body tube.


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## Monkey of Death (Feb 2, 2010)

Justin Case said:


> What tailcap do you have? This is what I have for my old E2:



That's the one I have.



> I would check the condition of your rubber button. It sounds like pressure from the top causes the plunger to push through the rubber button, which should hold the plunger in place. If the plunger gets pushed out the tube, then the wide flange can lose electrical contact with the exposed end of the body tube.


Good suggestion!
I checked and the button appears fine. Also, when you screw the cap down, doesn't the cap itself force the plunger into contact? 

With this in mind, I decided to try something. I got out my voltmeter, screwed the tailcap to the 'on' position and removed the head. This is where it lights if you touch the bulb, but not when you push it down. I got the voltmeter and read from the + end of the battery and the tube's edge. Good voltage. Then I pushed down on the batteries with the meter's probe and compressed the spring. The voltage stayed the same. But the bulb won't work in this position. :sick2: This should be the simplest circuit on the planet, so why won't it work??


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## Justin Case (Feb 2, 2010)

Yes, in principle the metal shell of the tailcap should also help to constrain the metal plunger from moving rearward.

When assembled, the plunger flange bears against the rubber flange of the button (which looks sort of like a top hat with a narrow brim). The rubber flange bears against the inside of the tailcap shell. If the button's flange is worn, it could conceivably allow some additional movement of the plunger. It takes only a little bit to lose electrical contact.

It sounds like you have a short somewhere. The E2 incan lamp shouldn't light up when you just sit it on top without any pressure. Only the center metal dome of the lamp contacts the top button of the 123A cell. The circuit isn't completed until the outer metal ring of the lamp contacts the top of the battery tube. Pressure then somehow breaks your short, but also doesn't give you a complete circuit.

I would check the E2 lamp. On the top of the plastic flange, there is a little U shaped cutout at the edge. You can see a solid metal wire that should be spot welded to the outer metal ground ring. Is that spot weld sound? If not, I can see how you might get some flex and lose contact between the wire and the ring.

Unfortunately, this explanation doesn't address why your Lumens Factory lamp also has the same symptoms. Plus, in re-reading your situation, I see that you burned out the stock E2 lamp anyway.


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## Justin Case (Feb 2, 2010)

With the EO-E2R lamp, it should light up when gently placed on top of the E2 battery tube only if the center dome contact touches the top button of the AW16340 cell *and* the metal lamp body touches the sides or top edge of the battery tube to complete the circuit.

Normally, when the LF lamp is installed in the E2 head, the lamp is centered in the battery tube and final ground contact is between the top of the battery tube and the metal flange of the LF lamp.

How are you making your ground contact when you rest the EO-E2R on top of the tube?

When you press down, at what point does the LF lamp go out? Immediately, after a little bit of travel, after a lot of travel, when the LF flange contacts the top of the battery tube?

Are your batteries in good shape in terms of the insulating jacket, no dents in the terminals, no visible impact damage, etc?


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## Monkey of Death (Feb 2, 2010)

Justin Case said:


> With the EO-E2R lamp, it should light up when gently placed on top of the E2 battery tube only if the center dome contact touches the top button of the AW16340 cell *and* the metal lamp body touches the sides or top edge of the battery tube to complete the circuit.



Correct, that is how I'm getting it to work (I have to tilt the lamp a bit to touch the side, but that is essentially how I'm doing it).



> How are you making your ground contact when you rest the EO-E2R on top of the tube?


The center lamp contact rests on the battery contact point. This leaves the lamp sitting a bit above the tube (due to the spring). So I tilt the lamp slightly to one side so it touches the edge of the tube. And it lights (side note: the tail cap is screwed down into the 'on' position, btw).



> When you press down, at what point does the LF lamp go out? Immediately, after a little bit of travel, after a lot of travel, when the LF flange contacts the top of the battery tube?


Almost immediately. The slightest bit of downward travel and all goes dark. I should point out that I'm very careful to continue to make solid contact with both points as I do this. Even with good contact, it goes out. Oddly enough, when I release pressure, it doesn't come back on. If I remove it from contact then immediately reposition it, it lights again. But once it goes out and I release pressure and it returns to the working 'zero' point (with good contact), it won't come back on until I break contact and restart.



> Are your batteries in good shape in terms of the insulating jacket, no dents in the terminals, no visible impact damage, etc?


Batteries are brand new and, as far as I can tell, show no signs of damage.

And thanks so much for all the thought you're putting into this. I really do appreciate it! :thanks:


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## Justin Case (Feb 2, 2010)

Probably need some photos of all of the relevant areas and pieces at this point -- same sort of photos I posted of your tailcap, battery photos, body tube photos of the neck and tail, perhaps a shot down the bore of the body tube, and a shot of the LF lamp (perhaps bottom contact view).


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## jaundice (Feb 2, 2010)

Hmmm. It sounds like the process of compressing the tailcap spring might be the problem. Is the tailcap spring compressing to the point where it rotates off the negative terminal?

I see that Justin Case is on the case. I've dealt with Justin extensively, and I can tell you that he's the man when it comes to flashlight circuits!

-John


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## Monkey of Death (Feb 3, 2010)

Justin Case said:


> Probably need some photos of all of the relevant areas and pieces at this point -- same sort of photos I posted of your tailcap, battery photos, body tube photos of the neck and tail, perhaps a shot down the bore of the body tube, and a shot of the LF lamp (perhaps bottom contact view).



Sorry about the delay, I was having FTP issues getting the photos uploaded. They're just quick shots, but I think they'll work. If you need anything else, different, closer, better or whatever, let me know! Thanks again!


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## Justin Case (Feb 4, 2010)

I think you need to resize your photo or at least re-arrange it so that they don't span so many pixels horizontally.

Let me re-cap to see if I understand everything.

- This odd problem occurred suddenly and without warning, so presumably there has been no known damage, impact, or other potential source for the failure

- You checked the resting voltage of your 123A cells (not a definitive test of cell function).

- You swapped tailcaps with your wife's E1. Your E2 tailcap worked on her light, but her E1 tailcap didn't work on your light.

- You swapped heads with your wife's E1. Your E2 head worked on her light, but her E1 head didn't work on your light.

- You did not conduct your "press the lamp down" test with the stock E2 lamp. It is now burned out anyway, so you can't do this test.

- If you sit your LF HO-E2R lamp (sans the rest of the head) on top of the loaded battery tube and with the tailcap screwed down to constant-on, the lamp lights (you angle the LF lamp so that the circuit is completed -- the center button contacts the battery top button and the metal side of the lamp contacts the battery tube).

- If you start to press down on the LF lamp, it almost immediately goes out. Releasing the pressure doesn't not result in the lamp coming back on. You have to break contact and then re-establish contact (without pressing down) for the lamp to come back on.

Questions:

Did you swap in any fresh or otherwise known-good 123As before you burned out your stock E2 lamp by running it with 2xAW16340?

How did you power the E1 head on the E2 body, and the E2 head on the E1 body, since one is a 2x123A light while the other is 1x123A?

When you screw down the tailcap, do you screw it down firmly or just enough to get constant-on? Has constant-on operation worked reliably in the past?

Did you try the following: Back out the tailcap. Press the tail button hard to ensure that the light is in the "on" state (for example, hold the light vertically, with tailcap down, and press the tailcap button hard into a tabletop). Now, conduct your LF lamp test (lightly resting on the tube vs pressing down on the tube).

If you insert the bare metal plunger switch into the tail end of the E2 tube, does the flange mate evenly with the end of the tube? No high contact spots that might result in just a single point of contact, rather than a circular line of contact?


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## Monkey of Death (Feb 4, 2010)

Justin Case said:


> I think you need to resize your photo or at least re-arrange it so that they don't span so many pixels horizontally.



Done- made a single column so they don't go wide.



> Let me re-cap to see if I understand everything.
> 
> - This odd problem occurred suddenly and without warning, so presumably there has been no known damage, impact, or other potential source for the failure
> 
> ...


All of this is exactly correct. However, I had my wife pick up a factory MN03 bulb at a local store near her work today to try out. When she gets home with it, I'll let you know how it fares in the "press the lamp down" test. And I'll use the regular CR123 batteries this time 



> Questions:
> 
> Did you swap in any fresh or otherwise known-good 123As before you burned out your stock E2 lamp by running it with 2xAW16340?


Yes, and got no result.



> How did you power the E1 head on the E2 body, and the E2 head on the E1 body, since one is a 2x123A light while the other is 1x123A?


I cheated  
I swapped the lamp assemblies inside the heads. Just wanted to make sure there wasn't some issue with the head itself. I'd already learned my lesson about wrong lamp/battery combos...



> When you screw down the tailcap, do you screw it down firmly or just enough to get constant-on? Has constant-on operation worked reliably in the past?


Firmly. And I've never had an issue with it.



> Did you try the following: Back out the tailcap. Press the tail button hard to ensure that the light is in the "on" state (for example, hold the light vertically, with tailcap down, and press the tailcap button hard into a tabletop). Now, conduct your LF lamp test (lightly resting on the tube vs pressing down on the tube).


I just tried this. I started with everything at rest (not pushing down on the lamp or the tube). No light since the tailcap isn't being pushed down. When I push the tube down and the tail switch makes contact, the lamp lights up. Release pressure on the switch, it goes out. Repeat without moving lamp and it lights and goes out in sync with the tailcap being compressed. Now push down on the lamp and everything goes dark. Now, if you relax the pressure on the lamp but keep it in contact with the batteries and the tube and let up on the tail, when you push back down on the tail, it lights. If you recall, when the tail is locked down, I have to lift to bulb to reset it get it to work again. So breaking the circuit at the switch is like resetting the bulb.



> If you insert the bare metal plunger switch into the tail end of the E2 tube, does the flange mate evenly with the end of the tube? No high contact spots that might result in just a single point of contact, rather than a circular line of contact?


Looks like a flat, tight seal. I took the E1 and shone it up the tube to see if I could see any light between the pieces and it looks like a very good fit.

Thanks again for all your help and I'll let you know how the factory bulb does when I get it in a few hours.


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## Monkey of Death (Feb 4, 2010)

*Update!*
I got the new factory bulb and tried the "touch then push" test. It lit and then... stayed lit?!? So I put it in the head unit, screwed it on and everything works like it is supposed to.

So my guess it that my new Lumens Factory bulb is bad and shorts out when pressure is applied to the base. How good are they about sending replacements if what they sent was bad?

The thing that has thrown me is when I touched the old lamp, which I thought was burned out, to the 2 AW16340 cells. It DID light up for a split second. Maybe it was blown, but the higher voltage made a brief jump across the filament break that the lower, original voltage couldn't do? I don't know, but that's the best I can come up with. In any case, that made it seem like it wasn't a bulb issue. And then the LF bulb lighting at rest and then not just made it weirder.

Well, I'm thrilled I have a light again! Even if it isn't upgraded (yet). Will send off an email to LF to see about another bulb. A huge, *HUGE* "Thank You" to everyone who had suggestions. Especially to Justin Case, whose patience and input led me down the path of trying another new bulb. You guys rock!! And once I get this one set, I may still look into upgrading my two Streamlights...


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## ampdude (Feb 4, 2010)

If it flashed it was never blown until the two IMR16340's were introduced to the MN03.


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## Monkey of Death (Feb 4, 2010)

ampdude said:


> If it flashed it was never blown until the two IMR16340's were introduced to the MN03.



That's what I thought, too. But then why did it stop working in the first place? It was on at full brightness and then "Bam!" it wasn't. I even changed batteries just to make sure and got nothing. Even if I never figure out what happened, I'm just happy to have my favorite little light working again!


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## Justin Case (Feb 4, 2010)

Could be one or more factors. Hard to say after the fact.

I've had SF lamps with broken filaments that were very hard to detect. They looked intact unless you put a magnifier on them and looked carefully. And a little shake and you'd get continuity sometimes as the pieces swung by and touched each other.


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## ampdude (Feb 4, 2010)

Justin Case said:


> Could be one or more factors. Hard to say after the fact.
> 
> I've had SF lamps with broken filaments that were very hard to detect. They looked intact unless you put a magnifier on them and looked carefully. And a little shake and you'd get continuity sometimes as the pieces swung by and touched each other.



Incan strobe mode, right? :laughing:

Haha, I had a blown P90 a little while back that I could not see the blown filament, which is unusual. But I did not put a magnifier on it. Hey I still have that P90... and a cheap 2x magnifier I think.. I'll check it out soon


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## Monkey of Death (Feb 5, 2010)

It is definitely the 'new' bulb.

I took the batteries out and stacked them on the table with the "-" contact sitting on a wire. I set the LF bulb on the "+" terminal and touched the wire to the side. It lit up, of course. Now I gently pushed down on the lamp and the light went out immediately. Just like inside the flashlight. I guess there's a short in the lamp base.

I sent an email to LF last night and got a very quick response. They're sending me a new bulb and they're going to check it out in the E2 they have in the office before sending to verify it works! Can't ask for more than that! :thumbsup:


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