Fenix L2D-Q5 damaged/issue

I have been using a new Fenix L2D-q5 since Sept.-08. I has worked great.

It suffered a fall from a moving bicycle to pavement a month or more ago - it seemed to work fine when I checked it and I went on with using it. But since perhaps about then or somewhat after the brightest mode has not been lasting for more than 30min or so, switches to low mode even on fresh batteries.

At first I did not correlate the drop and the change in performance, I assumed it was worn/old NiMH batteries. I bought a maha c9000 and new Sanyo 2700mah batteries conditioned then and had same issue (and found my older batteries were as good as new. I know I could have tested w/Alkaline, but wanted the charger anyway)

Recently the issue got worse, high mode only lasted a few minutes, then seconds, then not all all, just a brief flashing of lights, or low mode no matter the button presses. (but still would flash in that mode, but low) I cleaned contacts (battery and housing) with no change.

In desperation (I needed light to get home) I whacked it moderately on a wooden table. Amazingly it fixed all issues and even high mode worked great. Highest mode worked for at least 40min with stability even on a vibrating bicycle, haven't checked more than that.

This is not a long term fix, nor reliable of course.

Any suggestions to repair short of sending to Fenix for repair. I am good with electronics, but not surface mount (not sure what is inside as I have not opened it or if it is possible to do so) I am not against sending it back for repair of course, unless there is something relatively easy to check for and re-solder or otherwise fix.

I will in parallel buy a new Fenix light. I believe the nearest 1:1 replacement is the L20+. Are there other high output AAx2 models to consider that a similar to L2D? I have not kept up with latest since September.

Thanks-
Al

noisebeam said:

Are there other high output AAx2 models to consider that a similar to L2D?

Click to expand...

There are a lot of 2 AA lights on the market now, but the two that seem to get the most use around CPF are the Fenix LD20 and the Quark AA^2.

http://www.4sevens.com/product_info...=1620&osCsid=703a8d5496901e2e27392eb70586f977

The Nitecore D20 is the Cadillac of 2 AA lights, but it was just way too expensive for me to even remotely consider.

http://www.nitecore.com/products/d20/

I went with the Fenix LD20 because it was compact, lightweight, simple to operate, and I had great results with my first Fenix product, a TK40. Here's the LD20.

http://www.fenixlight.com/viewnproduct.asp?id=52

I can't comment on the other two lights because I've never used them but I sure do love my new LD20.

Sure it doesn't just need a cleaning? My LD20 was acting strange - would flash on high then immediately go to low. The light had been sitting for a while, so I just gave the contacts a quick clean and it's working good as new.

and check if the insides of the tailcap is loose

kts said:

and check if the insides of the tailcap is loose

Click to expand...

+1

AFter you clean the contacts and check to make sure the tail cap ring is tight, if those don't cure the problem...I have a suggestion for a different bike light. I have used the L2D Q5 since they became available and still use them on one of my bikes. I tried out the 4sevens Quark Turob AA2 and it screams! The larger head gives the light throw with the the 50% brighter LED when running at max. That big head also lets it run very cool and you have two programmable modes out of 8. I run mine at max and medium which is selected by rotating the head. Rather heavy for a bicycle helmet light but also works very well on the bars.

I'm thinking of trying a Peak El Capitan single AA light that runs the new Cree XP-G R5 LED through an optic so it stays small, will run on Eneloops, lithium AA or 3.6V lithium-ion.

My favorite 2 AA light is an Eagletac P10A2. It has two levels, medium and high - no strobe or sos [thank God]. The modes are chosen by turning the head, so you know which mode it will be in upon startup - a great UI in my opinion. In high mode it is the brightest light in Selfbuilt's 2 AA roundup review. It runs great on NiMH or Energizer lithiums. Eagletac also makes some other 2AA lights, some with more modes, but I haven't used those.

Thanks for the suggestions.

I think there may be some contact issue, not certain. I did clean them this morning and clean them again before my night ride this evening.

First battery (sanyo nimh 2700, burned in and confirmed good) lasted 1.5hrs, basically normal. But it ended with flickering light, 2nd battery set (tested good as new 2100mah imedions) started flickering immediately, lasted only 10min until it dropped to low only mode. But tapping on unit hard got it to work again temporarily.

I'll try cleaning all contacts (both the battery and body to head and endcap contacts) again. The end cap is tight as is the inner insert in it as best as I can tell.

I am now back to my theory of something loose inside contained areas of either head or tailcap causing intermittent electrical contact. I did a very good cleaning of battery & housing contacts for both end cap and head and the issue is still there.

At first the light worked correctly, but soon into my ride I hit a bump and it went dim. When in this dim state I can toggle between fast blink or steady with head twisted closed and with head open can toggle between the three steady modes (but all dim as in the lowest setting) and the SOS pattern - all five modes though are the same very dim brightness level.

Once at destination I bumped light on leg a few times to no effect, then bottom of hard sole shoe and it worked again just as it should.

There is no rattle or anything that seems loose.

Given the dim mode operation - is this most likely an issue in the head or tail cap? If it could be an external contact (battery or housing to caps) issue, which one?

Any further thoughts?

I would guess that some surface mount solder connection cracked inside the head. This usually doesn't happen easily because of the low weight of the components, but a drop, or more accurate the sudden stop at the end , can generate quite high g-forces...
As we are talking about a sub micron crack here, that connection might "toggle" with any external shocks easily.

I never opened up one of my Fenix light heads, maybe that isn't even possible...

Yes, agreed. After taking apart the end cap, cleaning & checking it and continuing to find the issue where the light goes dim, then a whack 'fixes' it, that it is the head. I also assume there are surface mount components in there.

It does not look like it is possible to open without perhaps a special tool or method. Even if I could open it, it is likely I won't be able to see any damage, let alone fix it.

That said, has anyone opened up a head of the L2D? - I am curious and don't mind risking more damage. I will also contact Fenix to find out if I can just buy a replacement head. (They don't make this model anymore though, right?) Thanks.

noisebeam said:

... 2nd battery set (tested good as new 2100mah imedions) started flickering immediately, lasted only 10min until it dropped to low only mode. ....

Click to expand...

I run my LD20 on my handlebars for my commute to/from work. 2100mah Imedions are nice batteries, but they are awful in cold weather. I had almost the same issue start with me this winter. Turbo only lasted 15-20 minutes then it went to low. Batteries tested good (indoors on the charger and in the LD20). I was really scratching my head and thought my LD20 had some bizarre issue that would never get fixed - until I put Eneloops in it. Now everything is fine. The imedions are now my Keyboard/Mouse (indoor only) batteries. I have no idea how Sanyo 2700's work in the cold. They do advertise that their Eneloops are specially designed to work well in a wider range of temperature than normal NiMH.

I know you say a stiff whack on the head of the light made it work again, so this may not be your issue, but worth considering. It is cold this time of year. Does the issue follow with the cold weather? Did it happen to be warm the day rode with it for 40 minutes after smacking it on the table? I've also had the ring in the tail cap come loose just a bit and give issues. Like the other posters have stated - just tighten it a bit.

Good luck, I hope you get it figured out.

I am certain it is not the batteries. Issue happens indoors 75F as well on freshly charged batteries of all kinds. I have a new set of Sanyo 2700mah that have gone thru Burn In cycle on maha C9000 reported out 2600+mah capacity and fresh off a charge the issue still happens at room temp.

Question now is how I can open the head. Seems it does unscrew, the L2D head as two grooves, I assume the slightly wider one toward the front is the break point - I am not strong enough even with rubber bands for grip

https://www.candlepowerforums.com/threads/152212

So somehow there is at least partial access.

I also just bought a L20+ from 4sevens.

Noisebeam, have you tried bypassing the tailcap to verify it is not the problem? This involves removing the tailcap and then using a metal paperclip or equivalent to connect the battery directly to the non-anodized body. You can even change modes by quickly breaking and re-establishing contact.

Opening up older Fenixes (L2D) is not hard to get to the emiiter, but getting to the circuit board is next to impossible with destroying the light.

The newer Fenixes are glued tight, I've never gotten one open...

Thanks. I won't bother trying to open it up then. Still has some use as I can bang it into operation and the intermittent fail not an issue if I have a parallel backup light always ready. (whether camping or cycling)

I will try the tail cap bypass too, if I can get the darn thing to stop working again, ha ha. It is working now and no amount of tapping, bumping, twisting, etc. will stop that. Just like taking your car to the repair shop and the problem goes away, but no doubt will redevelop once I need to use it again and I am far from a paperclip.

I just got the LD20 today and initially I am a bit disappointed relative to the L2D.

The negatives include:
-Smaller hotspot, less beam width. The L2D was already a bit on the narrow side as a cycling headlight.
-A quite dark ring around the hot spot. Distracting when cycling on dark roads as moving stuff goes thru beam and changes illumination.
-The non-turbo modes seem dimmer. Maybe it is the beam color fooling my eyes. I prefer brighter low mode as when turbo doesn't have enough power to sustain the L2D automatically switches to low mode which lets me continue cycling until I get to a place I can stop and swap batteries, a dimmer low mode will make that less possible.

Neutral:
-A much warmer beam color.

Positive:
-Nothing I note yet. Hopefully it will last longer on turbo mode. Right now I get ~1:30 and would prefer about 5min longer to get me to a stop point on my weekly night ride.

gunga said:

Opening up older Fenixes (L2D) is not hard to get to the emiiter, but getting to the circuit board is next to impossible with destroying the light.

Click to expand...

The intermittent drop to low power mode was annoying me, too, but today, I succeeded in removing the Circuit board from the L2D head. It's obviously just glued into the front cap and is composed of two boards (both at least two-sided).

Mine probably had gotten lose already from opening up the front part where the Emitter is located using the tubing method described elsewhere. I was able to pull the whole part out after de-soldering the wires and slightly rotating the circuit board with combination pliers.



I removed the red rubber-like glue and re-soldered the SMD parts on the top circuit board (couldn't de-solder the bridge between the two boards with my current equipment).
At least for now the low and high power modes are working correctly again. I hope this will last for a while.