EBay seller selling fake LED's (non functional).

[sleemanj]

Out of interest, what voltage and current limit did you test with, and what, if any, was the actual current drawn?

(I'm trying to be careful not to teach a grandmother to suck eggs here - but well aware that sometimes people forget that LEDs really need a current limit :-)).

Behind the yellow plastic is NOTHING.

Looks like on one of those photos you were scraping pretty hard.  Note that the die are very small, half a millimeter or so across and can easily be pushed off the substrate and "vanish" (I just tried it myself with the one I pulled apart) looking like just a spec of dirt or something if you can find it. 

When I disassembled mine I was very careful and used the tip of a knife to cut and peel away the silicone to reveal the die.

[sotos]

Except led’s he sells perfumes, Christmas lights, woman’s wrist watch, woman’s shorts, dresses, cats dog sleep warm bed house. What did you expect?

[Towger]

It was running off 25volts so I could take the photo 50 dies in total.

Yep. Thats a 50W module. I'll try one of mine and see how much power it draws, unfortunately they are at work and I am off until Tuesday.

[dannyf]

I am sure will have the money back, but will have 10 pcs of small alu heatsinks

That's why the story (or more precisely this kind of stories) never made sense to me: in the end, they seller would have spent the postage and potentially some on the goods (if as others alleged he is just a middleman).

What did he get in return? Nothing.

Why would anyone do that?

[mamalala]

Lovely advanture. Started to read a bit this thread and grr... postman at the door. My ebay-china delivery of the day and boom... the leds were in, 10 pieces, wanted to use them in macro photography. ALL FAKE. Behind the yellow plastic is NOTHING. I am sure will have the money back, but will have 10 pcs of small alu heatsinks

This is the item

http://www.ebay.com/itm/131100399580?var=430266495460

this is the seller

http://www.ebay.com/usr/eshop2098?_trksid=p2047675.l2559

At least the product photo seems to be right. There are no die's to bee seen there. Normally one can just see the separate LED die's under the silicone. But not in those images. Sure, doesn't help with the seller selling fakes, but still... He could go all-out and claim "product as shown in the image" and be fine, since in the image these modules are empty.

Greetings,

Chris

[London Lad]

I am sure will have the money back, but will have 10 pcs of small alu heatsinks

That's why the story (or more precisely this kind of stories) never made sense to me: in the end, they seller would have spent the postage and potentially some on the goods (if as others alleged he is just a middleman).

What did he get in return? Nothing.

Why would anyone do that?

Exactly, the LEDs aren't 'fake' and there is no intention to defraud people out of 99p, either the two cases we know of here are the buyers not finding the dies or the seller has a faulty batch that were improperly manufactured.

[mamalala]

I am sure will have the money back, but will have 10 pcs of small alu heatsinks

That's why the story (or more precisely this kind of stories) never made sense to me: in the end, they seller would have spent the postage and potentially some on the goods (if as others alleged he is just a middleman).

What did he get in return? Nothing.

Why would anyone do that?

Those sellers are usually nothing more than box-pushers. They get boxes of stuff, if needed repackage them into smaller qty's, and then sell them. Most of the time they have no clue about what they sell. Just compare the eBay descriptions of the articles, from different sellers. Quite often these descriptions are 1:1 copied from elsewhere, including typos and stuff (yes, i know that often a single seller also appears under many eBay names, but i mean really different sellers).

So if they get fakes they will likely be totally unaware of that. Luckily so far i never had a problem with stuff from Chinese sellers. On the contrary, i always got quick service from them, items re-sent if lost or broken, or the money reimbursed. And if something would really go wrong, i could always open a case with eBay and PayPal and get the money back that way. This is where PayPal is really the only thing to use: buying from Chinese sellers? Use PayPal only, to have at least a good chance to get the money back if the seller wants to play stupid.

Greetings,

Chris

[sleemanj]

Do you see any traces of conductor there??

Even in the  working led i took apart i could not find the conductor,  exact same construction soft silicon.

Again, the die are VERY small, it is easy to scrape them off without finding them if you are not careful.  The conductors, I never located any discete bond wires in my (previously) working unit which i disassembled and documented already above, but again it was working before i tore it apart so there was definately a conductive path somewhere but even with magnification i failed to find one,  again, this was a (previously) working unit.

l'm not saying you are wrong, just that it would be easy to accidentally lose the dies (if present) if you are roughly scraping out the silicone, and never find them.  And never see any bond wires even when you find the dies (if present).

[London Lad]

The bond wire are much smaller than 1/10 mm

[London Lad]

I'm not trying to convince you (or anyone else) that the dies are not missing, just that if they are missing its most likely a manufacturing fault and not deliberate.

I don't know what size the bond wires are but the ones I've seen look considerably smaller than 1/10 mm

I ordered some of the same LEDs that the OP bought so I'll be interested to see when they arrive.

[SeanB]

Send the reply to Ebay complaints dept, as the doing of business outside the Fleabay purview is frowned on.

[London Lad]

Send the reply to Ebay complaints dept, as the doing of business outside the Fleabay purview is frowned on.

I think the seller means contact them directly via the ebay message system rather than opening a case.

[neslekkim]

Send the reply to Ebay complaints dept, as the doing of business outside the Fleabay purview is frowned on.

I think the seller means contact them directly via the ebay message system rather than opening a case.

I find it more and more difficult to contact an seller without opening an case these days, on ebay.com it opens case, on ebay.co.uk it still allows you to contact seller without opening case.
Have one going now, were I bought an stepup converter http://www.ebay.com/itm/141015393957 and I got some led bulbs instead.. damn..

[dannyf]

there is always incentive to make business of anything.

It is hard to make a business out of buying parts, paying postage (however inexpensive it is), shipping a part over and getting nothing for that.

I believe that this business model works as shipping from china is much much cheaper than anything in the world.

As long as you have to pay for postage, no matter how much cheaper it is, that business model makes zero sense to me.

[dannyf]

10 out of 100 will make noise,

Well, out of the two cases of "fake" leds we have here, both complained, and 1 is getting a full refund and you can tell us where you stand on that.

So if your experience is representative, 100% of the customers will make noise;

If your experience isn't representative, ...

[Kjelt]

I think a lot of people might not even check the leds until it is too late or don't bother raising a case and take the loss.
Let's say it in another way if you had a business selling a product X and you had a couple of complaints that product X was garbage, would you still be selling them or would you start an investigation and till that time take the product offline. Think there you have a big difference between a good seller and a i don't give any s*it seller. 

[dannyf]

I just described a possibility.

In that case, using a 10% probability of claiming refund to refute a substantial probability of claiming refund isn't too strong.

[sleemanj]

the dimensions of the led's I am expecting to see is something like on the photo below. I saw very small leds on circuits like on arduino etc. Makes me feel insane if I have to think that the power led's on a 10w led could be even smaller than those ones!!   

http://litbimg4.rightinthebox.com/images/384x384/201207/cvoomh1342600566664.jpg

in the working one i disassembled ALREADY DOCUMENTED IN THIS THREAD the die are NOT VISIBLE unlit through the silicone and as Ihave already posted they measure, o.59mm WITH MY CALIPERS directly measuring them after excavation, and that is probably slightly overread.  about  half of  a millimeter each side.

Comparing to "very small leds on circuits like arduino" is silly, they are bare die, not a discrete  led with a casing and such soldered onto a heatsink, it is just a tiny grain of appropriately doped silicon bonded by some means to an aluminium substrate.

As I have already posted the conductive path is not visibly apparent even with silicone removed, perhaps if i used a microcope i might have found them, obviously there was one because the led was working before i destroyed it.  It's possible that the substrate itself has a part to play there.

[dannyf]

SO PLEASE

It is helpful in a discussion to have an open mind. The fact that others have observations contradicting to yours doesn't by itself mean they are wrong. However strongly you believe in your observations and your ability to interpret them correctly, your experience is just as anecdote as the next person's.

Hope it helps.

[amyk]

Just to clear up a few misunderstandings...

"Die" can be both plural and singular.

The visibility of the die through the phosphor depends on the concentration of phosphor in the silicone. Warm white LEDs will have a higher concentration and therefore look more opaque than cool white. Here's a good comparison from a seller of these: http://image.dhgate.com/albu_297105739_00-1.0x0/high-power-10w-warm-white-white-led-lamp.jpg When the light is to be made warm enough, the phosphor will look completely opaque.

Regarding ampacity of bond wires, look at these documents:
https://www.idt.com/document/atc/power-systems-design-estimating-bond-wire-current-carrying-capacity
http://ece.wpi.edu/analog/resources/wire_current_handling.pdf
http://www.palomartechnologies.com/blog/bid/53773/Gold-Ball-Bonding-for-LEDs-and-High-Power-Applications

That 1A is spread across 3 parallel strings, so there's ~333mA in each one. The first linked document suggests that a 1 mil copper wire 3mm long would already be capable of carrying 560mA. 1 mil is 25.4um -  and pretty much invisible to a human eye. If you've ever seen the bond wires of a MOSFET rated at >10A continuous you'd be surprised the first time how thin they are. Here's a 15A 2N3055 with the dimensions marked. Note the diameter of the bond wires relative to the die.

[sleemanj]

SO PLEASE: tell us, what kind of led did you dissassambled. Do you have photo, dimensions? I sent clear photos. For a 10W led that has to deal with almost 1A @12V, what is the minimum thickness of the wire? You say that this would be not visible with eyes? I will drop whatsoever beginner electronist belt and move to hairdrasser

This thread you are posting in.  It includes all the details and photos of the previously working unit I disassembled, it also includes photos proving the unit was working.

https://www.eevblog.com/forum/reviews/ebay-seller-selling-fake-led's-(non-functional)/msg425931/#msg425931
https://www.eevblog.com/forum/reviews/ebay-seller-selling-fake-led's-(non-functional)/msg426172/#msg426172

It is a 10W unit.  3 columns of 3 die.

Die are not visible through the silicone.

Die are squares of 0.59 mm diameter, measured with my digital calipers (but possibly overread slightly if there was any silicone still sticking to the edges of the die).

Here are some more photos
  http://imgur.com/a/gePGS
The middle die from the exposed column is missing because I pushed it off yesterday to see how hard it was, it was easy.

[Corporate666]

10 out of 100 will make noise,

Well, out of the two cases of "fake" leds we have here, both complained, and 1 is getting a full refund and you can tell us where you stand on that.

So if your experience is representative, 100% of the customers will make noise;

If your experience isn't representative, ...

you made a very wrong assumption in calculating your statistics. I wouldn't have described if I do not see this thread. We have all the 99.999% of the buyers whose behaviour we do not know and we cannot make any strong assumption. I just described a possibility. Not visible in which country you are, but it is generally very easy to notice buyers behaviour. I lived lot's of places in Europe. In Germany people would be very upset if they are are screwed up for even 1 cent. I agree with that. It is not about being "small" it is about showing that it does not work. Here in Belgium the "screwing up" works at industrial case. Insurances and other services are very bad, they cheat, they send out double invoices. What is the business model? There will be people who do not bother and pay! And beleive me: hear from lot of people: yes I preffer to pay rather than fight... and often they are right... the energy you invest is high. The same here... How much are you willing to pay to get your 1$ back? No threshold? Yes there is a threshold... So not sure if you as a buyer will win. But if you don't win, the seller wins, and the dollars ad up. Had another bad experience with ebay, where I order small items, all together 150$. The business model was: he lowered the price for lot of items. He was selling non-existent items under the price of market, so everybody was buying lot of trendy stuff. The guy suddenly disappeared. He was a seller in Germany. Apparently he run away with several millions he "made" during these weeks! Those times (~15 years ago) that was possible on ebay... Probably now not. People are inventive in how to find business... Not everbydoy is honest like us 

There is no way anyone is selling fake non-working items on eBay as a calculated ruse to make money.  eBay watches closely the feedback and number of cases, and even if a seller is selling thousands of items per day, if they are getting a lot of cases, they get banned from eBay.

This eBay seller is getting more than 400 feedbacks per day - which means they are probably selling 1,000 to 1,500 items per day.  They are not trying to be a big name in the LED business.  Their business is buying wholesale lots of stuff at various Chinese outlets and listing it all on eBay.  Somewhere, somehow a batch of junk LED's was made.  Maybe they were photo samples.  Maybe someone screwed up at the factory and the machine that puts the dies on didn't run, who knows.  Point is, those were ultimately sold (probably numerous times) and this seller got them at some auction or as part of a huge lot of parts - and listed them all on eBay.

The idea that they are selling dozens of legit items and then using that as a front to unload fake LED's just doesn't make sense.

And Chinese customer service is nothing like Western service.  "refund" is a foreign word to them... that's why they want to offer partial refunds.  They don't know what dies are, they don't know what LED's are, they don't know what fake LED's are - it's just a box of stuff they bought as part of a container load of parts.

The thing to do is just ask for a refund.  It would be polite to do it through a message rather than opening up a dispute first.   But if they don't reply, open a dispute and get your $$ back. 

[London Lad]

There is no way anyone is selling fake non-working items on eBay as a calculated ruse to make money.  eBay watches closely the feedback and number of cases, and even if a seller is selling thousands of items per day, if they are getting a lot of cases, they get banned from eBay.

This eBay seller is getting more than 400 feedbacks per day - which means they are probably selling 1,000 to 1,500 items per day.  They are not trying to be a big name in the LED business.  Their business is buying wholesale lots of stuff at various Chinese outlets and listing it all on eBay.  Somewhere, somehow a batch of junk LED's was made.  Maybe they were photo samples.  Maybe someone screwed up at the factory and the machine that puts the dies on didn't run, who knows.  Point is, those were ultimately sold (probably numerous times) and this seller got them at some auction or as part of a huge lot of parts - and listed them all on eBay.

The idea that they are selling dozens of legit items and then using that as a front to unload fake LED's just doesn't make sense.

And Chinese customer service is nothing like Western service.  "refund" is a foreign word to them... that's why they want to offer partial refunds.  They don't know what dies are, they don't know what LED's are, they don't know what fake LED's are - it's just a box of stuff they bought as part of a container load of parts.

The thing to do is just ask for a refund.  It would be polite to do it through a message rather than opening up a dispute first.   But if they don't reply, open a dispute and get your $$ back.

Spot on.

I import thousands of Chinese components and assemblies every month and despite the distance, culture and language differences we have many positive business relationships spanning more than seven years.

[mamalala]

-> I went today to the local retailer. Saw some 10W and 20W led based flood lights. The leds were visible. I think I have good eyes, could see through the silicon that actually the 9 leds are in series (maybe I am wrong), contrary to what I thoug that there would be 3 lines of 3 in series

I have about 20 of these 10-watts floodlights here. Half of them cold-white, the other half warm-white. In every one of them the 9 dies are visible, and all of them are in 3 rows with 3 dies each. They are all effectively in series, since they all run roughly at around 30 volts @ 300 mili-amps. There are 10 watt chips available that have a 3s3p configuration, that is, three parallel strings of 3 dies in series.

However, i had a 20  watt and a 50 watt quality LED here as well, and in those it was nearly impossible to see the single LED dies. Only under a bright light i was able to "see" the spots. But then, the 20 watt one was around 30 dollars, and the 50 watt one was around 70 dollars. That is, they really were quality chips, with well-specced characteristics.

Those cheap Chinese LED's are far from that, of course.

Greetings,

Chris

[David_AVD]

... but out of the 10 noone reacted to any voltage from 0 to 12 V.

Some of the high power LEDs (like the 20W white ones I use) need 18-20V to work.  I don't recall what voltage they start illuminating, but 12V may not be enough.

The easiest way to determine the Vf of the LED is to feed it from a much higher voltage (maybe 24V or higher) via a fairly high value resistor (say 10K).  It may not be very bright, but it will be visible.