Warning - Fake MJ16012 transistors on eBay - Page 1
Forum section: electronics / repair

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 10, 2016, 04:57:37 pm
content: Hi group,I have to report that I was victim of a fake transistor scam on eBay.***************************************************************************************UPDATEThanks 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.*************************************************************************************************StoryI 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:The breakdown voltage is 340V.This is the measured breakdown voltage with the Base-Emitter open:The measured breakdown voltage is 110V.This is the specifications:For good measure this is the current gain:The gain is around 250.And specification show that the gain should be around 30:Here is a picture of the fake transistor: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 SemitronusIf you have bought any of these, I suggest that you check them before use.Regards,Jay_Diddy_B

author: Rasz
author_rank: Super Contributor
timestamp: October 10, 2016, 05:19:57 pm
content: Quote from: Jay_Diddy_B on October 10, 2016, 04:57:37 pmwhat you do is-pen ebay dispute: received counterfeit goods-document-demand full refundit is ILLEGAL to ship counterfeit goods internationally, ebay will tell you to destroy themsellers 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).

author: edavid
author_rank: Super Contributor
timestamp: October 10, 2016, 06:00:51 pm
content: Quote from: Rasz on October 10, 2016, 05:19:57 pmAs you might have guessed from the seller name "semitronus", they are located in... the US.

author: Rasz
author_rank: Super Contributor
timestamp: October 10, 2016, 07:02:06 pm
content: Quote from: edavid on October 10, 2016, 06:00:51 pmnot 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

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 10, 2016, 07:27:06 pm
content: FWIW, HV switching BJTs are still alive and well, if you can stomach putting in a mod for a replacement package.Tim

author: harrimansat
author_rank: Regular Contributor
timestamp: October 10, 2016, 07:36:01 pm
content: Hi, can you please check max collector current?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 10, 2016, 07:36:44 pm
content: Hi,I de-capped the transistor. Here is the picture: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

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 10, 2016, 07:41:13 pm
content: Quote from: harrimansat on October 10, 2016, 07:36:01 pmHi,I am sorry, I don't understand the question, what would you like me to measure?Can you explain?Regards,Jay_Diddy_B

author: Habropoda
author_rank: Regular Contributor
timestamp: October 10, 2016, 08:04:48 pm
content: 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."

author: Rasz
author_rank: Super Contributor
timestamp: October 10, 2016, 09:42:18 pm
content: Quote from: Jay_Diddy_B on October 10, 2016, 07:36:44 pmcan 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 byhttp://bradthx.blogspot.com/2016/04/counterfeit-2n3055-transistors-from-ebay.htmlhttp://www.hifi-forum.de/viewthread-185-10652.htmlhttps://translate.google.com/translate?hl=en&sl=ru&u=http://www.telemaster.ru/fuflo/&prev=searchand many others that silicon goop is the trademark of Shenzhen counterfeits

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 10, 2016, 10:09:51 pm
content: HQuote from: Rasz on October 10, 2016, 09:42:18 pmI 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:RCA used metal clips, instead of bond wires. Here is a couple of pictures showing the inside of the dead transistor.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 numberRegards,Jay_Diddy_B

author: lowimpedance
author_rank: Super Contributor
timestamp: October 10, 2016, 10:25:07 pm
content: 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 ?.

author: kulky64
author_rank: Regular Contributor
timestamp: October 10, 2016, 10:38:58 pm
content: Was this transistor decapped on a lathe?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 10, 2016, 11:00:05 pm
content: Quote from: kulky64 on October 10, 2016, 10:38:58 pmYes, 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.Here is another picture with a transistor mounted ready for de-capping:Regards,Jay_Diddy_B

author: Cubdriver
author_rank: Unknown
timestamp: October 10, 2016, 11:26:01 pm
content: Quote from: Jay_Diddy_B on October 10, 2016, 11:00:05 pmThat's the first question that popped into my mind, too. Nice decapping jig!-Pat

author: Rasz
author_rank: Super Contributor
timestamp: October 11, 2016, 12:13:12 am
content: looks like this fakethis is how you buy them, unmarked and prerusted (maybe siglent makes them?)http://www.elektroda.pl/rtvforum/viewtopic.php?p=15042053#15042053interestingly this lot of fakes was already in US when listed on ebay

author: Merlot1970
author_rank: Contributor
timestamp: October 11, 2016, 12:37:53 am
content: Well...That transistor def. looks like piss poor construction. I only buy ON Semiconductor products from Mouser or Avnet Express...Works every time

author: edavid
author_rank: Super Contributor
timestamp: October 11, 2016, 02:28:19 am
content: Quote from: Merlot1970 on October 11, 2016, 12:37:53 amIt doesn't work so well with discontinued parts like the MJ16012But, perhaps Jay would like to splurge on some MJ16018s:http://www.alliedelec.com/solid-state-manufacturing-mj16018/70348185/

author: TheBay
author_rank: Unknown
timestamp: October 11, 2016, 11:27:14 pm
content: What spec do you need, just had a look through my parts draw and I have the following:Genuine NOSMotorola 2N2947RCA 2N3442Any of those two suitable?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 12, 2016, 12:44:33 am
content: Quote from: TheBay on October 11, 2016, 11:27:14 pmThank 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 minIc >10AHFE under these conditions around 5-8good switching performance.I have made another eBay purchase this time from eBay sellerfourgtfourgt 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 MJ16012And this is a photograph of the Semitronus (Fake) MJ16012In hindsight the radius on the top of the can doesn't look right, it has too big a radius.Refund newsI 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

author: Rasz
author_rank: Super Contributor
timestamp: October 12, 2016, 01:26:11 am
content: Quote from: Jay_Diddy_B on October 12, 2016, 12:44:33 amyou didnt even leave him negative feedbackhttp://feedback.ebay.com/ws/eBayISAPI.dll?ViewFeedback2&userid=semitronus&iid=-1&de=off&items=25&searchInterval=30&which=negative&interval=180&_trkparms=negative_180looks like more people bought fakes from himyou can report his auction as selling fakes

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 12, 2016, 01:52:10 am
content: Hi,There are quite a few fakes on the semitronus eBay listings apart from the MJ16012.Here are a couple of examples: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

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 12, 2016, 04:22:12 am
content: I've never seen so shiny a TO-39Tim

author: engiadina
author_rank: Contributor
timestamp: October 12, 2016, 06:57:08 am
content: 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 ...

author: setq
author_rank: Frequent Contributor
timestamp: October 12, 2016, 08:02:29 am
content: 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.

author: Zucca
author_rank: Unknown
timestamp: October 12, 2016, 12:00:38 pm
content: Thanks, now I want a curve tracer

author: JoeO
author_rank: Frequent Contributor
timestamp: October 12, 2016, 01:25:17 pm
content: Quote from: engiadina on October 12, 2016, 06:57:08 amI just searched for goodtronic on ebay. They are gone. Either they changed their name or ebay took them off.

author: setq
author_rank: Frequent Contributor
timestamp: October 12, 2016, 01:28:31 pm
content: They're probably called excelentronic now or something.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 12, 2016, 02:50:53 pm
content: ***************************************************************************************UPDATEThanks 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

author: Rasz
author_rank: Super Contributor
timestamp: October 12, 2016, 09:17:11 pm
content: 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