Light suddenly got dim and kept that way? Romisen NC-3

[swbluto]

Hello, I recently received a Romisen NC-3 LED flashlight from deal extreme. Looking at the comments at deal extreme, it appeared to be an adequate performance "good quality" flashlight for $16 as it was made by Romisen. I got it today and I admit I was impressed given my past LED flashlight experiences ($2 checkout counter types with 10+ LEDs and "reverse clicky" type.).

Everything was going great for the first 10 minutes, except, it suddenly started flickering and I thought "Oh god, no, not again."(The previous flashlight I had would get really weak and just flicker; I chocked it up to a cheap $2 flashlight). And then... it got really dim. And stayed that way.:shakehead Good thing is - It stopped flickering! Bad thing is, it's now practically useless. (Yes, the led is apparently "on", but it's very weak as in, there's no detectable light output but the LED die is faintly lit.)

So, thinking that maybe my brand new batteries had just died or something after what was like 11 minutes of use, I checked them using my voltmeter. The alkalines are both at 1.56 volts each. I'm thinking that's not it.

So, what's the likely problem and how would I fix it?

Also, can anyone recommend a "rugged, durable" flashlight if I can't make this flashlight work? I just want a flashlight that works with decent performance. Oh, and a forward clickie.

 

[kramer5150]

First remove the tailcap and use a paper clip to touch -B to the body tube. If you get consistent light then the problem is in the tailcap. Post back that result...

DX does have an RMA procedure. If you follow it to a"T" they will honor it. Details are on their www site. I have had to send stuff back to their RMA office in Miami. In all it usually takes me a good ~20-25 days to get RMAs handled through them, and get corrected items at my doorstep.

My standard no hastle, no pain 2xAA recommendation = Fenix TK20 from a reputable retailer. (bolded in purpose)

This is more than durable enough for most.
http://www.candlepowerforums.com/vb/showthread.php?t=219738&page=4

 

[wingnut86]

Just send the DX one back and order an upgraded one from shiningbeam. Like the Q5 or WW version. Then if there is a problem, you can get it resolved almost hassle free.

 

[swbluto]

So I connected the B- with the body tube with the paperclip and I got the same results: LED die faintly lit, and no visible light output. It switched through the "3 modes" like it did originally, though in a very dim form.

Would you consider deal-extreme a reputable retailer? It seems like people sometimes get "different versions" of a product, so I would guess there's something funny going on.:duh2: Can anyone recommend reputable retailers?

(Like one comment from the NC-3 flashlight that I bought stated that there's didn't have a forward clickie and it seemed to be the "luck of the draw".)

 

[swbluto]

Just send the DX one back and order an upgraded one from shiningbeam. Like the Q5 or WW version. Then if there is a problem, you can get it resolved almost hassle free.

How would a potential problem be less of a hassle than this light is?

And, is shiningbeam a website?

 

[kramer5150]

Would you consider deal-extreme a reputable retailer? It seems like people sometimes get "different versions" of a product, so I would guess there's something funny going on.:duh2:

Yes and No...
I have always gotten what I ordered, no hastles. Unfortunately half of my DX lights were either DOA or flickering and required a complete part by part teardown and rebuild. So while they do a good job delivering, their suppliers have NO quality control at all, and DX does not do any incoming/outgoing inspection.

Unlike Bryan (shiningbeam) who personally inspects everything coming in and going out. (at least thats what he once told me)

 

[swbluto]

Thanks for the lay of the landscape.

I guess I won't be purchasing more than "simple" electronics from deal-extreme in the future.

Do you know who I could buy a fenix tk20 from? It appears shiningbeam doesn't have it.

So... is it the driver that's likely bad? Do you know what part usually goes bad on drivers that needs replacement? I'd imagine there's a single likely failure mode for drivers, so it'd be nice if anyone told me the secret. I have a job with SMD pcb repair and testing, so replacing a part wouldn't be a big deal for me. However, replacing the driver completely might be more sensible, I'm guessing, since the original design may have been inadequate. I could also test the LED with some current with the lab power supply, but I don't know how easy it would be to test.

Edit: I just checked out the RMA process. Apparently, they just ship out a new one. If the new replacement becomes defective (This one was working great for 10 minutes before self-destruction: how long can I reasonably expect a similar product to last?), then it seems to be a defective overall outcome. I'd rather repair it, if I can as I don't want to wait a month for the possibility of a light that *might* last longer than 10 minutes - the fact that it wasn't DOA and didn't destroy itself *immediately* seems to suggest a likely defective part or design.

 

[kramer5150]

Do you know who I could buy a fenix tk20 from? It appears shiningbeam doesn't have it.

Theres at least half a dozen reputable www retailers who sell the TK20. fenix-store is the brands outlet, lighthound is my personal fave, battery junction...etc...

So... is it the driver that's likely bad? Do you know what part usually goes bad on drivers that needs replacement? I'd imagine there's a single likely failure mode for drivers, so it'd be nice if anyone told me the secret. I have a job with SMD pcb repair and testing, so replacing a part wouldn't be a big deal for me. However, replacing the driver completely might be more sensible, I'm guessing. I could also test the LED with some current with the lab power supply, but I don't know how easy it would be to test.


It could be any number of things in there that failed, its really had to say without further dissection. If you are into DIY (and it kind of sounds like you are). The head comes apart in 4 main pieces, bezel/reflector, pill, body and an adapter piece to house the pill. Make sure all the threads are clean and free of anodize and grease build up. I use isopropyl alcohol 99% and a paper towel and give it a good wipe down, metal to metal is what you are after.

There is also a VERY critical insulator gasket that should be adhered over the LED solder pads. like a disk-doughnut adhesive sheet. A good percentage of the DX lights I have taken apart (as well as P60 modules) were missing this piece. It protects the +LED and -LED from shorting out to chassis ground through the back side of the reflector.

Theres also the possibility of a poorly heatsinked LED. About 1/3 of the DX lights I own have had poorly adhered LEDs to the pill. For whatever reason the LEDs were not glued down well enough to allow heat to conduct from the LED to the pill.

So with these things in mind, your failure could have resulted from any number of things. Heres some pics...







if you get the light taken apart down to the pill, you should be able to wire connect a battery straight to the pill and get bright light out of it. like this:

 

[wingnut86]

How would a potential problem be less of a hassle than this light is?

And, is shiningbeam a website?

I don't know where you are located, but he is located in the US. So the process of a return would be very quick if you are here as well. And as Kramer said, Bryan supposedly checks the lights before shipment.

 

[kramer5150]

I don't know where you are located, but he is located in the US. So the process of a return would be very quick if you are here as well. And as Kramer said, Bryan supposedly checks the lights before shipment.

Based on my experience I believe this statement to be true. I can see a part of my reflector back side where he took a dremel or a file to it and de-burr'd a sharp edge, to provide clearance for the LED. I am positive it didn't leave the factory in China this way:thumbsup:, and I have done similar mods to my DX lights to get them up and running reliably.

 

[Ajay]

I don't know where you are located, but he is located in the US. So the process of a return would be very quick if you are here as well. And as Kramer said, Bryan supposedly checks the lights before shipment.

www.shiningbeam.com
BROOKLYN, NY 11223

Represent!

 

[hyperloop]

How would a potential problem be less of a hassle than this light is?

And, is shiningbeam a website?

DX quality control (or lack thereof) strikes AGAIN!

Drop them a Customer Service Express ticket and see what they say, they're pretty decent about it. If you want Romisens, get them from www.shiningbeam.com they have a discount code (CPFuser) as well.

EDIT: just read the rest of the posts, i got my TK20 from www.4sevens.com they have a discount code (CPF8) too.

 

[swbluto]

So, I took apart the light down to the pill and attached 3 volts (power supply) to the +/- terminals. The same behavior was found, and the light was drawing .24 amps in "high mode" (.24 amps in low mode, and .1 amps average in "strobe mode"). I'm told this has a 800 mA driver, so I would expect .8 amps I believe.

Do you know how to take the circuit board? It's hard to tell whether it's soldered to the tube or just to a removable component within the tube.

BTW, if deal-extreme lacks quality control, then wouldn't that also imply that Romisen lacks quality control? A good manufacturer tests their products, no? Or are budget manufacturers the exception?

 

[wingnut86]

BTW, if deal-extreme lacks quality control, then wouldn't that also imply that Romisen lacks quality control? A good manufacturer tests their products, no? Or are budget manufacturers the exception?

Basically, the way I see it, is that the QC for many of the cheap Chinese made lights, is left up to the dealer.

The Romisens at shining beam are his own special orders, thats why they cant be found elsewhere, he is in contact with the manufacturer I believe, So he probably insists that they perform some quality control.

About DX though, I have never really had a problem. One light had unacceptable machining, but as they say, "you get what you pay for" so I lived with it.

 

[wingnut86]

I'm told this has a 800 mA driver, so I would expect .8 amps I believe.

Since its a boost circuit, the current draw, (from the battery) would have to be higher then 800mah to supply 800mah to the led.

 

[kramer5150]

So, I took apart the light down to the pill and attached 3 volts (power supply) to the +/- terminals. The same behavior was found, and the light was drawing .24 amps in "high mode" (.24 amps in low mode, and .1 amps average in "strobe mode"). I'm told this has a 800 mA driver, so I would expect .8 amps I believe.

Do you know how to take the circuit board? It's hard to tell whether it's soldered to the tube or just to a removable component within the tube.

Hard to say, there can be a HUGE difference in the manufacturing methods form one DX light to another. Even between two identical model lights. Mine is set up like a typical aluminum pill. There is a brass ring pressed into the Aluminum. The DC-DC board is soldered onto the brass ring at 3 locations around the perimeter. If yours is like mine, you can use some solder braid or a solder-vac and remove the solder. The DC-DC board will just pull right out.

Actually before you do that, you might want to try and reflow the solder. It could be as simple as a cold solder joint.

Also, double check and make sure they put that adhesive insulator over the LED. Without this, it won't make any difference what you do to salvage the pill... if this is indeed shorting and damaging the circuit.

Those current readings are way off. Could be a toasted emitter, defective board or both.


BTW, if deal-extreme lacks quality control, then wouldn't that also imply that Romisen lacks quality control? A good manufacturer tests their products, no? Or are budget manufacturers the exception?

The quality levels of any product line are dependent on the standards imposed by the parent company. Fenix is going to have their QC standards outlined for their fabricators in China. Eagle Tac, Quark are likewise going to have their standards. I have found that the budget manufacturers seem to have lower standards than the higher end ones... regardless of country of origin. So yes good manufacturers do seem to QC inspect carefully and more stringently than the budget ones. You get what you pay for, generally. www retailers like Shiningbeam, who do incoming and outgoing inspection on even the cheaper products are the exception... unfortunately.