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

[sleemanj]

The yellow filling is just colored silicone rubber, so is fairly easy to seperate out. Another set of LED's we have from else where are filled with a solid compound rather than a rubber compound.

Well, I'll be.  It certainly looks like in that image that they are completely empty.

I found a seller which looks like they are selling the same ones (same images, same selections, same text) on the au ebay site and ship to NZ, for a buck each (10W).  Have bought a couple to satisfy my curiosity.

[jancumps]

cool

[M4trix]

Have bought a couple to satisfy my curiosity.

In case you receive same fake LED's, what will you do? Report the seller? 

[SpectrHz]

What a strange attitude you have... Regardless, it is interesting that they are totally empty... I wonder, would it even be worth leaving the elements out, at the risk of being called out for it? Or maybe just a manufacturing fluke?    seems like a lot of effort to go to for a blatant scam.

[JoeN]

Get it right with the seller first please. He's got 150.000+ positive reviews.

Don't pay much attention to this number. The ebay accounts are bought and sold all the time. 100K+ is typically grown sequentially by several owners; you will be obviously dealing with the last one only.

I found places with 1K-10K feedback to be most adequate. Couple of 150K+ shops didn't even pay attention to my negative fb and ppal disputes when I had issues with their wares.

The last time a seller ignored my ppal dispute I had my money back in 3 days after the escalation to a claim, the least amount of time it takes.  It's good when they do that, PayPal will side with you.  They have to respond.

[amyk]

The yellow filling is just colored silicone rubber

It's silicone with the yellow phosphor, which is what a real working white LED (with die inside) of that construction would use too:
http://www.digikey.com/en-US/articles/techzone/2011/feb/phosphor-film-conversion-for-white-leds

Or maybe just a manufacturing fluke?    seems like a lot of effort to go to for a blatant scam.

That's what I'm thinking as well  - maybe they ran out of die somehow (and didn't notice), or the die dispenser malfunctioned, and the rest of the production line just continued filling in the blank leadframes with encapsulant.

[London Lad]

Bound to be a mistake if there really is no die but they are 99 pence including shipping to the UK !!!!
Hardly worth starting a war over

[TerraHertz]

Okey doke.

The yellow filling is just colored silicone rubber, so is fairly easy to seperate out. Another set of LED's we have from else where are filled with a solid compound rather than a rubber compound.

But anyway, pictures aren't going to help for some of you I know, but c'est la vie. We think you really need to investigate for yourselves from this point on.

Cool, thanks for showing. You know if you'd posted that in the first place, it would have saved some time.
"pictures aren't going to help for some of you I know" - That's unreasonably defensive. I think most people who asked you about it just wondered why you didn't post the pics originally.

Anyway, the next question is, is it the real phosphor blue to yellow re-emitter compound, or just a batch of silicone someone mixed up? That would differentiate between 'production line goof', and outright intentional fraud.

If you get a blue LED, and shine it through a fragment of the filler you cut out, is there any evidence of yellow fluorescence?

[all_repair]

You guys are getting it wrong as you are assuming the sellers are just like you who have engineering background and likely honest in nature.  You can find these direct Chinese sellers not on ebay, but on Taobao.  They give good value and good service.  Those who sell China stuff on ebay are just reselles and traders, pure bussinessmen, slightly better than bankers and 2nd hand car salemen.  They work to get their ratings up and have learned the ebay and able to game the ebay system.  Ebay is not much better when tings do not work out well.  These resellers when things do not turn out well shall manage the system.  If they can get replacement from original seller in China, they shall assist.  If they could not, and if the value is small, they shall absorb to buy the rating as you can see from some of buyer who sing and dance when he got his.  When the amount is bigger, they shall walk away with no hesistation at all, but they shall manage the situation.  They are not well like by original sellers in China as they pressed down price, drag payment and give a bad impression of the China product.  The original sellers shall tell up front the problem, fake, broken, 2nd hand, option for cheap cnc controller, option for expensive controller, etc   but all these declarations are intentionally left out.

[miguelvp]

So I was out of a job for a while and with a mortgage, what did I do, I start doing the ebay thing and even if I had a couple of close calls I remedy the situation immediately and kept my 100% rating.

Haven't done it since 5 years when I got another job (an awesome job at that) but I call BS when you claim ignorance as a seller.

[mrflibble]

If you get a blue LED, and shine it through a fragment of the filler you cut out, is there any evidence of yellow fluorescence?

Good question, and indeed a reasonable experiment to try to differentiate between "outright fraud" and "could be an honest mistake".

[sleemanj]

I found a seller which looks like they are selling the same ones (same images, same selections, same text) on the au ebay site and ship to NZ, for a buck each (10W).  Have bought a couple to satisfy my curiosity.

My two leds arrived today, and somewhat disappointingly, they work perfectly.

They were shipped in anti static bags inside a bubble envelope.

The filling appears to be silicone (I haven't pulled it out but it feels a bit squishy) the same as the original poster's.

You can't see any dies through the coating, nor bond wires, and I was thinking they were fake.  But nope, I hooked em up with a 1k resistor and brought the voltage up slowly, all 9 dies in each were well lit up with 5 mA.  Since it's not heatsunk I didn't bother pushing a proper amount of current into it, 5mA was enough to cause the old retina burn in.

So, on the basis of that, I can at least say that not all these "10W" for a Buck led's are fakes, the two I got aren't, and they look identical to the ones that the original poster got.

For sake of completeness, here's the listing I bought:
http://www.ebay.com.au/itm/141172937767?var=440244682801&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
but looks like they've gone out of stock of the 10W ones.

Photos attached.

[miguelvp]

Cool, maybe I'll revive my 1920x1200 lcd panel projector project after all.

But for what is worth, your seller is a different one than his seller, looks like he still has a lot of them left from the picture that he posted earlier, maybe hook a 9V power supply and make sure it's the right polarity?

[London Lad]

The dome being soft is quite common in high power leds these days

[amyk]

If you're willing to sacrifice one of those working ones, it would be great to see what the die inside looks like. They're tiny, and the bond wires are also equally thin, so they can be pretty difficult to spot if encased in a mass of silicone. I'm not surprised that the die isn't visible - it's surrounded by the yellow phosphor, otherwise you'd see blue light.

The dome being soft is quite common in high power leds these days

Definitely, it's a cheaper process than epoxy encapsulation.

[sleemanj]

If you're willing to sacrifice one of those working ones, it would be great to see what the die inside looks like.

Done.

Careful picking away revealed one row, I couldn't see any bond wires, either they are too small to see with the naked eye, or perhaps embedded in the silicone I removed (I did look, but couldn't see anything), or perhaps there is some other means of connecting them, possibly using the substrate.

Two rows were killed in the process, not sure if it was that I killed one of the dies or the electrical connection.

I was able to light a couple of the dies in the exposed row just using my multimeter diode test and probing pretty much on top of the die either side.  At least a couple of times, then I guess the coating was scratched off.  Anyway, yeah, they are indeed blue.

The die measure 0.59mm according to my calipers.

So there you go, that's what's inside these leds.

[AmmoJammo]

While we're on the topic on leds (I bought some after reading this thread) how hot should they be kept to? what's the maximum temperature this type of led should be run at?

[dannyf]

I've been asked to keep quiet about it (by the seller).

They actually asked you that, or you think they asked you that?

A screenshot of the conversation / communications would be helpful.

If indeed they asked you to be quiet, you should probably approach ebay to alert them of a fraud.

If they didn't ask you to do what you think they asked you to do, you should probably approach ebay to alert them of a fraud too.

[sleemanj]

While we're on the topic on leds (I bought some after reading this thread) how hot should they be kept to? what's the maximum temperature this type of led should be run at?

Cooler the better.  You probably want to keep the heatsink temperature down to about 70'C to 80'C.  Don't even think about lighting one up full power without a heatsink for more than a fraction of a second flash to check it's working.

About a year ago I did a quick google search for somebody and came up with the maximum silicon junction for the typical 1W type of led to be about 120'C, I'd guess that most of these power leds would be about the same.  I don't think I found out the thermal resistance junction to tab/case/pad though.

[AmmoJammo]

I bought some of the 50watt leds, rated upto 34volts input. At 34volts they draw about 550ma. Hmm.  Under 20watts...

[Kjelt]

huh? i thought farnell/element14 products are all genuine?

and 99,99% of them probably are, but things happen and they don't always buy directly from the semi fabs companies esp. with ONS, rare components that are no longer made or in small quantities. Hey it happens to the best of firms, if the DOD gets caught with their pants down it can happen to any firm.

[Towger]

I bought some of the 50watt leds, rated upto 34volts input. At 34volts they draw about 550ma. Hmm.  Under 20watts...

Their rating is in Chinese watts... I have a few 30W, 50W, and 100W white and RGB, from memory the 50w should draw around 1400ma at 34V.  Are you sure they did not sent you a 30W module... The 30W, 50W and 100W are in the same physical package.  Can you count the dies through the silicon?

[David_AVD]

Did you test them at all ?

[AmmoJammo]

I bought some of the 50watt leds, rated upto 34volts input. At 34volts they draw about 550ma. Hmm.  Under 20watts...

Their rating is in Chinese watts... I have a few 30W, 50W, and 100W white and RGB, from memory the 50w should draw around 1400ma at 34V.  Are you sure they did not sent you a 30W module... The 30W, 50W and 100W are in the same physical package.  Can you count the dies through the silicon?

I have this many!



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

[M. András]

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

and where are the pictures of it showing what you recieved?