Fenix L2S - failed to repair mode switching

Xe54

Enlightened
Joined
Sep 12, 2005
Messages
201
Hi:

I have a Fenix L2S that flickers out when the bezel (head) is loosened to achieve the "low" brightness setting.

I tried to fix it by:
1. Wire brushing the threads shiny clean.
2. Applying a coating of Nyogel 760G grease to both halves of the threads.
3. Reassemble and screw the threads back and forth a few times.

The result was that the light worked perfectly, but only for about 2 days. Then the threads must have oxidized again despite the grease so that it just won't light again in low mode.

I have considered silver filled conductive greases with low volume resistivities suitable for real current flow through the grease (see note below), but they are very expensive. I suspect that the machining tolerances on this light were loose, so that there's just too much space in there. Even a conductive grease might not fix it unless it is certain to also keep the Al surface from oxidizing again, which is difficult to guarantee.

Any ideas? Do you think conductive grease would fix it?

Note: There are "conductive" greases which are really not able to carry current but rather are designed for ESD dissipation. I doubt that these types are the answer here. Only the metal filled greases have low volume resistivities.
 

Gunner12

Flashaholic
Joined
Dec 18, 2006
Messages
10,063
Location
Bay Area, CA
It might be a connection problem. I've heard about the L2S, L2T and similar lights loosing low mode because of a short.

See if you can get a replacement. (where did you buy the light?)
 

datiLED

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Joined
May 9, 2006
Messages
2,022
Location
Atlanta, GA
From what you describe, it sounds like the connection to the brass pill (heatsink) has been broken. There is a wire from the driver that is soldered directly to the pill near the LED. This provides your low setting. The connection made when the battery tube contacts the circuit board provides your high setting. If the contact with the pill is lost, it will behave exactly as you indicate. Fixing the issue may be difficult, as the L2S is very hard to get the pill out of. Good luck! :thumbsup:
 

Jarl

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Jan 11, 2007
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Location
Southern UK
Or just email for a replacement if you don't want to faff around with pills, etc.
 

Gunner12

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Location
Bay Area, CA
If you are in the US, I think Fenix Store is the official Fenix place, so they should be able to fix the light for you(or get you a new one) if you really can't fix it.
 

Xe54

Enlightened
Joined
Sep 12, 2005
Messages
201
From what you describe, it sounds like the connection to the brass pill (heatsink) has been broken. There is a wire from the driver that is soldered directly to the pill near the LED. This provides your low setting. The connection made when the battery tube contacts the circuit board provides your high setting. If the contact with the pill is lost, it will behave exactly as you indicate. Fixing the issue may be difficult, as the L2S is very hard to get the pill out of. Good luck! :thumbsup:

The light works when the head is loosened and the threads are turned against each other with pressure a few times. Then it works while pressure is maintained on the threads.

I'm convinced the problem is due to the threads having loose tolerance and being oxidized. There is nothing wrong with the connection of the driver board to the head.

I'll look into warranty replacement...
 

buglight

Newly Enlightened
Joined
Dec 14, 2008
Messages
34
Location
Idaho
I just got a new L2D Q5 for Christmas and have the same problem. I emailed Fenix and got this:

Hello Chris Thank you very much for using Fenix light.
Actually, the low modes works when the light is a little loose, in order to lead the customer operate correctly, we make a video in our website, so here I direct the link to you, please visit for your reference.
http://www.fenixlight.com/czsl.asp
If the problem still exists, please feel free to contact us again.
Best regards!

[FONT=ËÎÌå]Sincerely Joyce [/FONT]
[FONT=ËÎÌå]Fenix Service Team [/FONT]
[FONT=ËÎÌå]Website: www.fenixlight.com [/FONT]
[FONT=ËÎÌå]Tel: 86-0755-29631183 [/FONT]
[FONT=ËÎÌå]MSN: [email protected] [/FONT]
[FONT=ËÎÌå]-----ÓʼþÔ*¼þ-----

Ö÷Ìâ: problem with L2D Q5
[/FONT]

[FONT=ËÎÌå]Hi, I just got a new L2D Q5 for Christmas and it worked just fine....the first day. the next day I clicked it on and it was in turbo mode. I 'light-clicked' as before to change modes and it started flashing. This is all the light will do now...either turbo or flash, none of the lower modes are working. I tried removing the batteries and re-installing; I tried another set of batteries...no change.[/FONT]


I loosened up the joint at the top of the battery tube and it worked. Why the heck would they design it this way?? seems pretty stupid to me.
If I tighten the thing down...normal finger-tight, not wrenching it :rolleyes: it goes into turbo only and rapid flash.
 

Marduke

Flashaholic
Joined
Jun 19, 2007
Messages
10,110
Location
Huntsville, AL
I just got a new L2D Q5 for Christmas and have the same problem. I emailed Fenix and got this:

I loosened up the joint at the top of the battery tube and it worked. Why the heck would they design it this way?? seems pretty stupid to me.
If I tighten the thing down...normal finger-tight, not wrenching it :rolleyes: it goes into turbo only and rapid flash.

It's the method by which you can get two unique mode groups. If you want modes with no moving parts, that's how plenty of cheap junk lights operate, and you have to cycle through countless unwanted modes to get to the two you use the most - the lowest and highest.
 

buglight

Newly Enlightened
Joined
Dec 14, 2008
Messages
34
Location
Idaho
It's the method by which you can get two unique mode groups. If you want modes with no moving parts, that's how plenty of cheap junk lights operate, and you have to cycle through countless unwanted modes to get to the two you use the most - the lowest and highest.

playing with it just now I noticed it has 4 modes...loosen the cap a little and get the normal 3...then, when in the 3rd/turbo mode I tighten the cap and get a a 4th/brighter one. Or, am I missing something...are these things supposed to do this? :p
 

Zatoichi

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Joined
Aug 29, 2008
Messages
1,099
Location
UK
playing with it just now I noticed it has 4 modes...loosen the cap a little and get the normal 3...then, when in the 3rd/turbo mode I tighten the cap and get a a 4th/brighter one. Or, am I missing something...are these things supposed to do this? :p

You should have 6 modes. Low, medium, high and SOS with the head loosened, and with it tightened you should have turbo and strobe.
 

TONY M

Flashlight Enthusiast
Joined
Jan 31, 2008
Messages
1,548
Location
Belfast, NI
I loosened up the joint at the top of the battery tube and it worked. Why the heck would they design it this way?? seems pretty stupid to me.
If I tighten the thing down...normal finger-tight, not wrenching it :rolleyes: it goes into turbo only and rapid flash.

I feel this is an excellent way of navigating through the modes.
I hope you have plenty of fun with the light now.

:welcome:
 

buglight

Newly Enlightened
Joined
Dec 14, 2008
Messages
34
Location
Idaho
You should have 6 modes. Low, medium, high and SOS with the head loosened, and with it tightened you should have turbo and strobe.
ah, thanks. None of the literature they sent in the box said anything about this :shakehead
now it makes sense
This is the first light like this I've had...used to 'on/off' :p
 

Marduke

Flashaholic
Joined
Jun 19, 2007
Messages
10,110
Location
Huntsville, AL
ah, thanks. None of the literature they sent in the box said anything about this :shakehead
now it makes sense
This is the first light like this I've had...used to 'on/off' :p

The spec sheet and instructions in the box (if you bought it new) have that information, as well as the dealer's website your purchased it from.
 

buglight

Newly Enlightened
Joined
Dec 14, 2008
Messages
34
Location
Idaho
The spec sheet and instructions in the box (if you bought it new) have that information, as well as the dealer's website your purchased it from.

ok, now I feel like a dork :banghead:

for some reason I thought everthing was controled by the tail switch...not turning the bezel...duh.....

...nevermind...
 

LED Flashlights.

Enlightened
Joined
Dec 16, 2007
Messages
206
Hi:

I have a Fenix L2S that flickers out when the bezel (head) is loosened to achieve the "low" brightness setting.

I tried to fix it by:
1. Wire brushing the threads shiny clean.
2. Applying a coating of Nyogel 760G grease to both halves of the threads.
3. Reassemble and screw the threads back and forth a few times.

The result was that the light worked perfectly, but only for about 2 days. Then the threads must have oxidized again despite the grease so that it just won't light again in low mode.

I have considered silver filled conductive greases with low volume resistivities suitable for real current flow through the grease (see note below), but they are very expensive. I suspect that the machining tolerances on this light were loose, so that there's just too much space in there. Even a conductive grease might not fix it unless it is certain to also keep the Al surface from oxidizing again, which is difficult to guarantee.

Any ideas? Do you think conductive grease would fix it?

Note: There are "conductive" greases which are really not able to carry current but rather are designed for ESD dissipation. I doubt that these types are the answer here. Only the metal filled greases have low volume resistivities.

I have a Fenix L2S and I know what you mean about the grease on the head and threads.

Don't clean it, just clean the contacts on the head with a small amount of rubbing alcohol on a Q-Tip.

Don't wire brush the threads. The grease is important to keep the threads nice and smooth.
 
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