EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: Jay_Diddy_B on October 10, 2016, 04:57:37 pm
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Hi group,
I have to report that I was victim of a fake transistor scam on eBay.
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UPDATE
Thanks to guidance provided in the forum I requested a refund through the eBay system.
Ebay policy:
"If a buyer suspects that an item is counterfeit, and there are strong indicators that the item is counterfeit, we don't require the buyer to return the item to the seller. The buyer agrees to cooperate with us to ensure the proper disposal of the item. In such instances, we refund the buyer for the full cost of the item and original shipping, and the seller reimburses us for the refund. The buyer may not sell the item on eBay or elsewhere."
I got the refund, from the seller, very quickly.
The catch is that I can not provide any feedback now on eBay. It is like this transaction never existed.
This loophole allow the sale of counterfeit parts to persist without warnings in the feedback system.
I have reported the item and several other items to eBay as being counterfeit, but as of now no action has been taken.
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Story
I purchased a total of 6 MJ16012 transistors, I needed two for the repair of an HP8662A RF generator with a damaged power supply.
Fortunately, I have a Tektronix 576 Curve tracer, so I checked the transistors before using them.
Bipolar transistors have a different breakdown voltage, depending on the base connection. The highest voltage is with the base-emitter shorted, the lowest voltage is with the base-emitter open.
Here are the test results:
This is the measured breakdown voltage with the Base-Emitter shorted:
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261606;image)
The breakdown voltage is 340V.
This is the measured breakdown voltage with the Base-Emitter open:
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261608;image)
The measured breakdown voltage is 110V.
This is the specifications:
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261610;image)
For good measure this is the current gain:
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261612;image)
The gain is around 250.
And specification show that the gain should be around 30:
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261614;image)
Here is a picture of the fake transistor:
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261616;image)
If I am reading the datecode correctly, this would be the 23rd week of 2015. I am sure that these parts were obsolete along time before this.
Does anybody know when on-semiconductor stopped making high voltage BJTs for smps?
I contact the seller, he told me he has sold hundreds no complaints, but will give refund if I return them.
I really want to leave negative feedback to warn others.
Seller's name is Semitronus
If you have bought any of these, I suggest that you check them before use.
Regards,
Jay_Diddy_B
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I contact the seller, he told me he has sold hundreds no complaints, but will give refund if I return them.
I really want to leave negative feedback to warn others.
what you do is
-pen ebay dispute: received counterfeit goods
-document
-demand full refund
it is ILLEGAL to ship counterfeit goods internationally, ebay will tell you to destroy them
sellers want return because they know it will be uneconomical for you due to scam China post is doing (almost free shipping out of china thanks to international post arrangements forcing international deliveries to be free for the sending country).
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sellers want return because they know it will be uneconomical for you due to scam China post is doing (almost free shipping out of china thanks to international post arrangements forcing international deliveries to be free for the sending country).
As you might have guessed from the seller name "semitronus", they are located in... the US.
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sellers want return because they know it will be uneconomical for you due to scam China post is doing (almost free shipping out of china thanks to international post arrangements forcing international deliveries to be free for the sending country).
As you might have guessed from the seller name "semitronus", they are located in... the US.
not really, and didnt bother looking it up, did just now and it appears this seller offers genuine surplus stuff, not cheap chinese junk, this makes me think OP should decapsulate one of the transistors to be 100% sure
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FWIW, HV switching BJTs are still alive and well, if you can stomach putting in a mod for a replacement package.
Tim
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Hi, can you please check max collector current?
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Hi,
I de-capped the transistor. Here is the picture:
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261633;image)
This has all the marks of a fake. There is no heat spreader. The die is much smaller than it should be. The bond wires are not thick enough. The die has been covered in white silicone rubber or something similar.
Regards,
Jay_Diddy_B
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Hi, can you please check max collector current?
Hi,
I am sorry, I don't understand the question, what would you like me to measure?
Can you explain?
Regards,
Jay_Diddy_B
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Rasz has it right; just dispute and document it. Ebay does NOT require you to pay return shipping in the case of defective or counterfeit goods, no matter where it is from.
The seller would like you to think you need to pay and will negotiate right up to the dispute deadline (a week I think) and then will issue a full refund with no return and will request you give them a five stars review. If Ebay steps in they will just issue a full refund with no return as long as you have good photos and documentation.
A good seller will just refund with no haggling.
Ebay policy:
"If a buyer suspects that an item is counterfeit, and there are strong indicators that the item is counterfeit, we don't require the buyer to return the item to the seller. The buyer agrees to cooperate with us to ensure the proper disposal of the item. In such instances, we refund the buyer for the full cost of the item and original shipping, and the seller reimburses us for the refund. The buyer may not sell the item on eBay or elsewhere."
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Hi,
I de-capped the transistor.
can you decap one of the broken ones?
it would be interesting to look at the supposed fake under the microscope, does onsemi etch its logo/mark on the die?
but judging by
http://bradthx.blogspot.com/2016/04/counterfeit-2n3055-transistors-from-ebay.html (http://bradthx.blogspot.com/2016/04/counterfeit-2n3055-transistors-from-ebay.html)
http://www.hifi-forum.de/viewthread-185-10652.html (http://www.hifi-forum.de/viewthread-185-10652.html)
https://translate.google.com/translate?hl=en&sl=ru&u=http://www.telemaster.ru/fuflo/&prev=search (https://translate.google.com/translate?hl=en&sl=ru&u=http://www.telemaster.ru/fuflo/&prev=search)
and many others that silicon goop is the trademark of Shenzhen counterfeits :(
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H
can you decap one of the broken ones?
snip ...
I don't have an original MJ16012 at the moment. The HP8662 signal generator power supply that I am attempting to repair used these transistors manufactured by RCA:
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261674;image)
RCA used metal clips, instead of bond wires. Here is a couple of pictures showing the inside of the dead transistor.
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261676;image)
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261678;image)
The die in the MJ16012 should be about the same size as the die in the HP original parts. There certainly should be a copper heat spreader. I would expect to see guard rings on the edge of the silicon die for a high voltage transistor.
I am substituting the original transistors with the MJ16012. I lived through the 'golden age' of BJT switching transistors working on offline SMPS and the genuine MJ16012s are about the best ones ever made.
I have never seen any text on a BJT or MOSFET die. I have seen lots of photographs of IC die with identification marks.
Why do they go to all this trouble to make garbage? With a little more effort they could make good working transistors and give them their own part number :-//
Regards,
Jay_Diddy_B
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Thanks for your efforts with the testing and decap of the two showing the differences. The RCA construction is most interesting.
I wonder what the fake transistor actually is and is it the general go to for all fake TO3's ?.
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Was this transistor decapped on a lathe?
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Was this transistor decapped on a lathe?
Yes, I made a fixture out of 2 inch diameter 6061 Aluminum so that I de-cap using a metal lathe. I faced the block, then I laid out the TO-3 hole pattern using a DRO on a milling machine. I tapped the holes for the mounting screws 6-32. The fixture centres the metal can on the axis of the lathe.
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261701;image)
Here is another picture with a transistor mounted ready for de-capping:
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261703;image)
Regards,
Jay_Diddy_B
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Was this transistor decapped on a lathe?
Yes, I made a fixture out of 2 inch diameter 6061 Aluminum so that I de-cap using a metal lathe. I faced the block, then I laid out the TO-3 hole pattern using a DRO on a milling machine. I tapped the holes for the mounting screws 6-32. The fixture centres the metal can on the axis of the lathe.
<images snipped to save space>
Regards,
Jay_Diddy_B
That's the first question that popped into my mind, too. Nice decapping jig!
-Pat
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looks like this fake
this is how you buy them, unmarked and prerusted (maybe siglent makes them?)
http://www.elektroda.pl/rtvforum/viewtopic.php?p=15042053#15042053 (http://www.elektroda.pl/rtvforum/viewtopic.php?p=15042053#15042053)
interestingly this lot of fakes was already in US when listed on ebay
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Well...That transistor def. looks like piss poor construction. I only buy ON Semiconductor products from Mouser or Avnet Express...Works every time :-+
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Well...That transistor def. looks like piss poor construction. I only buy ON Semiconductor products from Mouser or Avnet Express...Works every time :-+
It doesn't work so well with discontinued parts like the MJ16012 :-//
But, perhaps Jay would like to splurge on some MJ16018s: http://www.alliedelec.com/solid-state-manufacturing-mj16018/70348185/ (http://www.alliedelec.com/solid-state-manufacturing-mj16018/70348185/)
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What spec do you need, just had a look through my parts draw and I have the following:
Genuine NOS
Motorola 2N2947
RCA 2N3442
Any of those two suitable?
(http://i.imgur.com/imi5cJS.jpg) (http://imgur.com/imi5cJS)
(http://i.imgur.com/AvR3g1q.jpg) (http://imgur.com/AvR3g1q)
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What spec do you need, just had a look through my parts draw and I have the following:
Genuine NOS
Motorola 2N2947
RCA 2N3442
Any of those two suitable?
Thank you for the kind offer, but neither of these parts is suitable.
The application is an off-line switching power supply. The requirements are:
Vceo 400V min
Ic >10A
HFE under these conditions around 5-8
good switching performance.
I have made another eBay purchase this time from eBay seller fourgt
fourgt is 'Global Test Equipment' I talked them on the phone, they three pieces that were part of the inventory of spare parts. I good reasons to believe that they are genuine NOS.
They will be going on the curve tracer when they arrive.
This is a photograph of the fourgt MJ16012
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261951;image)
And this is a photograph of the Semitronus (Fake) MJ16012
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261953;image)
In hindsight the radius on the top of the can doesn't look right, it has too big a radius.
Refund news
I did get a refund for my original purchase. But it is very disappointing to see that the fake transistors are still for sale.
Regards,
Jay_Diddy_B
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I did get a refund for my original purchase. But it is very disappointing to see that the fake transistors are still for sale.
you didnt even leave him negative feedback
http://feedback.ebay.com/ws/eBayISAPI.dll?ViewFeedback2&userid=semitronus&iid=-1&de=off&items=25&searchInterval=30&which=negative&interval=180&_trkparms=negative_180 (http://feedback.ebay.com/ws/eBayISAPI.dll?ViewFeedback2&userid=semitronus&iid=-1&de=off&items=25&searchInterval=30&which=negative&interval=180&_trkparms=negative_180)
looks like more people bought fakes from him
you can report his auction as selling fakes
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Hi,
There are quite a few fakes on the semitronus eBay listings apart from the MJ16012.
Here are a couple of examples:
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261964;image)
(https://www.eevblog.com/forum/repair/warning-fake-mj16012-transistors-on-ebay/?action=dlattach;attach=261966;image)
How can I tell?
Simple, Motorola spun off the semiconductor business unit in 1999, so there should be no Motorola marked semiconductors with date codes after 99xx.
Regards,
Jay_Diddy_B
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I've never seen so shiny a TO-39 :-DD
Tim
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I bought some OpAmps recently from China. What made me look closer was the datecode. It claimed production in 2012, but the company was sold and renames in 2005. And the production of this OpAmp ended at about 1999.
Interestingly enough some of the chips worked, some did not. I put some samples under XRay to compare them to the original ones. That result was surprising. The ICs contained the correct die and looked similar to the original ones. But I found some who were reversed! Those did not work of course. Through some talks with the guys from the original manufacturer, I found out, that that they "lost" a complete container of those parts which did not meet the specs or did not work at all.
My parts must be from this batch, the chinese just relabeled them to sell them.
I filed a complaint to eBay but they demanded me to send the parts backon my cost. I had to go to the police and report a fraud issue. Only with a copy of the police papers eBay / PayPal returned my money an I could scrap the parts.
Guess what, this seller (goodtronic) is still selling those part.
Well ...
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This thread is interesting. Had some shonky 2n3055's off eBay before. Decapped one and the die was about 2mm across. I reckon total power dissipation would have blown it at around 30W. hFe was around the 150 mark as well which is waaay high.
Got some nice ones off CVC here in the UK in the end.
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Thanks, now I want a curve tracer
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I bought some OpAmps recently from China. What made me look closer was the datecode. It claimed production in 2012, but the company was sold and renames in 2005. And the production of this OpAmp ended at about 1999.
Interestingly enough some of the chips worked, some did not. I put some samples under XRay to compare them to the original ones. That result was surprising. The ICs contained the correct die and looked similar to the original ones. But I found some who were reversed! Those did not work of course. Through some talks with the guys from the original manufacturer, I found out, that that they "lost" a complete container of those parts which did not meet the specs or did not work at all.
My parts must be from this batch, the chinese just relabeled them to sell them.
I filed a complaint to eBay but they demanded me to send the parts backon my cost. I had to go to the police and report a fraud issue. Only with a copy of the police papers eBay / PayPal returned my money an I could scrap the parts.
Guess what, this seller (goodtronic) is still selling those part.
Well ...
I just searched for goodtronic on ebay. They are gone. Either they changed their name or ebay took them off.
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They're probably called excelentronic now or something.
https://www.youtube.com/watch?v=D0n8N98mpes (https://www.youtube.com/watch?v=D0n8N98mpes)
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***************************************************************************************
UPDATE
Thanks to guidance provided in the forum I requested a refund through the eBay system.
Ebay policy:
"If a buyer suspects that an item is counterfeit, and there are strong indicators that the item is counterfeit, we don't require the buyer to return the item to the seller. The buyer agrees to cooperate with us to ensure the proper disposal of the item. In such instances, we refund the buyer for the full cost of the item and original shipping, and the seller reimburses us for the refund. The buyer may not sell the item on eBay or elsewhere."
I got the refund very quickly.
The catch is that I can not provide any feedback now on eBay. It is like this transaction never existed.
This loophole allow the sale of counterfeit parts to persist without warnings in the feedback system.
I have reported the item and several other items to eBay as being counterfeit, but as of now no action has been taken.
*************************************************************************************************
Regards,
Jay_Diddy_B
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The trick might be to leave negative feedback first. From your post Im guessing you received an 'official' ebay refund, I never got that, just ordinary seller refunds - opened disputes asking seller for refund because counterfeit and was able to leave neg after receiving money, followed by 'y u do dis we so honest' messages while they still listed fake garbage :(