More fake parts on ebay - Page 1
Forum section: electronics / repair

author: ThermallyFrigid
author_rank: Frequent Contributor
timestamp: May 23, 2022, 04:45:17 am
content: This time it was transistors. E13009-2Fake Fake FakeOverheated and burned out at about 1/4 the rated current.ebay sellertoraysboostllc

author: DaJMasta
author_rank: Super Contributor
timestamp: May 23, 2022, 04:53:22 am
content: While it certainly happens, do you have any evidence or is this just an 'airing of grievances'?

author: ThermallyFrigid
author_rank: Frequent Contributor
timestamp: May 23, 2022, 05:06:15 am
content: Quote from: DaJMasta on May 23, 2022, 04:53:22 amAgreed.Occasionally and rarely it might happen that you get authentic, original high quality components on ebay, dirt cheap........but....my experience is that too often the old adage is spot on. I'm sure there are at least a few who would agree.Now, you might ask..."why keep ordering them from ebay then if they seem too often to be no good?Glad you asked! Only a bozo would do that, right? Well, You see, last year or two when I was still just jumping into the electronics hobby I was filling my little organizers with all kinds of components from all over the place.Some I'm just now getting around to using.Some are just outright empty cases....some kinda work, some work up to 1/3 their rated capacity etc. A FEW work as expected.Seems generally the semi's I bought on Amazon "generally" did a little better.I have had no problem with Semi's purchased on Mouser or DigiKey. (Imagine THAT!)"If a deal looks too good to be true, it's probably fake semi conductors from ebay.So it's just an airing of grievances

author: bdunham7
author_rank: Super Contributor
timestamp: May 23, 2022, 05:23:12 am
content: Care to describe the test conditions?

author: jfphp
author_rank: Regular Contributor
timestamp: May 23, 2022, 10:21:21 am
content: Most chinese parts are fake or out of order (X2216 for example : 100% dead on a batch of 10 !). The best I have seen was LTZ1000 with inside just an ordinairy zener !

author: wraper
author_rank: Unknown
timestamp: May 23, 2022, 10:31:08 am
content: While I agree that ebay is full of fakes, statement like "Overheated and burned out at about 1/4 the rated current." has no meaning in it. You can easily overheat and burn a transistor while passing 1/20 of its rated current. It's all about heat (power) produced within the part and transferring that heat away. And current by itself does not tell at all how much heat is produced.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: May 23, 2022, 11:07:56 am
content: I ordered FETs from China on ebay. Got NPN transistors.

author: max-bit
author_rank: Frequent Contributor
timestamp: May 23, 2022, 11:27:25 am
content: Currently, most products (semiconductors) from China (from the so-called MyFriend) are counterfeit.Today it is a real pathology.

author: ThermallyFrigid
author_rank: Frequent Contributor
timestamp: May 23, 2022, 12:04:18 pm
content: Quote from: wraper on May 23, 2022, 10:31:08 amI would respectfully disagree.It means that at least one person who bought those components from that seller experienced whet he believed to be "unacceptable" performance COMPARED to what the same device with ORIGINAL AUTHENTIC components would do.This was a simple remove and replace operation in a known otherwise perfectly working circuit in a purchased device and I have tested those fakes against original authentic (apparently) semi's.The entire batch was just as shoddy. Authentic E13009-2 components work perfectly...these fakes do not. It's that simple really.If you're looking for oscilloscope graphs and in-depth technical testing conditions that's not gonna happen here. Not even worth my time. I threw them away and moved on.Saying 'It has no meaning" simply means to you specifically it has no meaning. I'll bet you a buffalo nickle at least one person reading this will go "Yep, he's probably right" and avoid buying that particular component from that particular ebay seller. Mission accomplished.It's up to you what you do (or do not) take from this information given the honest posts of others and my attempt to be helpful and honest.It actually sounds as if you are defending the guy who sold me the bad semis ? Why on Earth would I randomly choose a random seller and semi to report about unless I had a real problem?I did. The semis were fakes. The shipping time etc were good.You're free to buy all of that same component from that same ebay seller that you wish. Good luck and let us know how it goes

author: ThermallyFrigid
author_rank: Frequent Contributor
timestamp: May 23, 2022, 12:10:21 pm
content: Quote from: bdunham7 on May 23, 2022, 05:23:12 amAs much as I intend to, I did in this thread. It was a simple remove and replace in a known otherwise working device.All from the batch in question failed. Replacements from different vendor worked as expected.The one thing I can say is that the TEMPERATURE of the fakes rose to over 130C - 150C fairly quickly before failing while the same authentic semis stabilized at around 46CIf you care to do proper testing I will send you one from the batch free of charge if you provide your shipping address.You are far more capable of proper in-depth test and analysis than I am.I'm sure all would really appreciate the exacts you find, your technical summary and exactly why they failed and how fake they actually are.I have two remaining...anyone else ?Waiting for your shipping address.

author: wraper
author_rank: Unknown
timestamp: May 23, 2022, 12:17:40 pm
content: Quote from: ThermallyFrigid on May 23, 2022, 12:04:18 pmMore than likely it could mean that component is genuine but person has no idea what he's doing. I commented the statement about current. I have no idea about the actual setup. It could be with or without an abnormal heating. It could be dropping 1V and dissipating just a little bit of heat or dropping 100V in linear operation and be scotching hot even with a large heatsink.

author: ThermallyFrigid
author_rank: Frequent Contributor
timestamp: May 23, 2022, 12:23:19 pm
content: Quote from: wraper on May 23, 2022, 12:17:40 pmThat's a rather paranoid responseDid you read the thread?Again, it was a simple remove the old one and solder in a new one. I think I've done enough soldering now to get that part right.To say I had "no idea what I was doing" is simply your opinion and insulting. The device is now working perfectly when authentic chips were installed.Are you the seller in question or in any way associated with by any chance?

author: wraper
author_rank: Unknown
timestamp: May 23, 2022, 12:24:15 pm
content: Quote from: ThermallyFrigid on May 23, 2022, 12:10:21 pmThen I guess your intention was to share nothing.QuoteYou did not say that at all.

author: ThermallyFrigid
author_rank: Frequent Contributor
timestamp: May 23, 2022, 12:26:32 pm
content: Quote from: wraper on May 23, 2022, 12:24:15 pmCare to explain why you are taking this comment about a semiconductor purchased on ebay personally ?To all others, I hope this helps you avoid fake E13009-2 Transistors on ebay

author: wraper
author_rank: Unknown
timestamp: May 23, 2022, 12:34:28 pm
content: Quote from: ThermallyFrigid on May 23, 2022, 12:23:19 pmDid you read what you wrote? You gave virtually no info other than 1/4 of rated current.QuoteYou say it now but not before my comment about particular statement.QuoteI have no idea about what you have or don't have an idea. Plenty of people on this forum complained that pass transistor in their 10A PSU quickly fails short even though it's rated for 50A. They don't take into an account they are dropping something like 40V and transistor is dissipating 400W.I agreed there are plenty of fake components on ebay. I wrote that:Quoteis deeply flawed statement. I made no judgment that transistor should be genuine whatsoever.

author: wraper
author_rank: Unknown
timestamp: May 23, 2022, 12:50:12 pm
content: Quote from: ThermallyFrigid on May 23, 2022, 12:23:19 pmIt wasn't an insult. And it wasn't even said about you in particular. I wrote "More than likely it could mean that component is genuine butpersonhas no idea what he's doing. ". It was about an abstract situation. Read it as person who says something like this may easily but not necessarily have no idea.

author: ThermallyFrigid
author_rank: Frequent Contributor
timestamp: May 23, 2022, 12:58:34 pm
content: Quote from: wraper on May 23, 2022, 12:50:12 pmIf you say so

author: all_repair
author_rank: Frequent Contributor
timestamp: May 23, 2022, 02:36:27 pm
content: Saying one getting fake semiconductors on ebay is not a morning breaking news on this forum. It is given, and to be 100% expected.What if one has no choice but to get the part on ebay. 100% testing, if it is not worth doing or not going to be done, forget buying from ebay. And fully expect to get fake, or defective parts. Once I have to source some obsolete parts from ebay. Ended up, I bought from 4 different sellers. Luck wasnt bad, only 1 of the sellers was selling defective. Got my money back for the defective parts, but I didn't give the seller hard time. He did offer some service in listing someone items, and unlikley he tested the parts, nor anyone reselling these parts did any testing. These sellers just not going to have the equipment, nor the time, nor the knowledge, nor worth their while..

author: bdunham7
author_rank: Super Contributor
timestamp: May 23, 2022, 03:05:04 pm
content: Quote from: ThermallyFrigid on May 23, 2022, 12:10:21 pmOK, that is much more information! Replacing a part in a complete unit and noting that Product A fails but Product B works seems a reasonable enough test. No need for advanced testing, but VCE, VBEand IBwould tell the story. Some reasons there is a bit of skepticism are 1) that seller looks pretty good 2) those transistors aren't really a target for counterfeiting as they are available from normal distributors for $0.50 or so, and 3) a transistor overheats because it is actually dissipating too much power for its package and heatsink.In this case, since you installed them in a device that you presume is good (due to it working with other known genuine transistors) the only reason I can think of that they would overheat and burn out is if they were actually dissipating too much power. And if the current was correct for the application--and the same that the genuine ones handled properly--then the explanation will be start with VCEbeing too high and thus the power dissipated much higher than expected. That could happen for a variety of reasons, depending on the design of the circuit and variations in batches of transistors. For example, in a circuit that expects the transistor to be saturated, a transistor with a lower current gain might not actually be quite saturated.So yeah, if you want to send me one, I'll take a look. I'll even order a genuine one in my next Mouser order--can you tell me exactly which one you ordered? Also please tell us what device/circuit the transistor is installed in, whether it is heatsinked or not and why you needed to replace it.

author: CaptDon
author_rank: Super Contributor
timestamp: May 23, 2022, 03:24:54 pm
content: I ordered some MJ10023 parts on Ebay from a Chinese huckster. Fake Fake Fake!!! Blew out instantly at power up!! Sadly, they were located in a difficult to access area of the power supply. I examined the remaining parts, the Motorola 'batwings' rubbed off with my fingers!!! Running a test on VCEBO showed a breakdown at around 100 volts for a part rated for 400+. If it is a Chinese seller just set your money on fire or else shop elsewhere. The U.S.A. is China's new landfill!!! The company I worked for ended up having some power darlingtons used on locomotives that were faster and had a higher collector current rating as well as a higher VCEBO stashed in a parts bin. They also had the same internal structure with the base pulldown resistors. They work great (and the price was right, we had hundreds of them considered obsolete by the company).Don't buy ANY Dallas Ramified Timekeepers from China!!! The fakers are so stupid, they put code dates on the parts that are newer than when Dallas stopped making the parts!!!

author: max-bit
author_rank: Frequent Contributor
timestamp: May 23, 2022, 07:20:22 pm
content: You may ask yourself "how wise" are those who buy these items in chinach and hope to buy the originals?

author: strawberry
author_rank: Super Contributor
timestamp: May 24, 2022, 05:37:04 am
content: people will buy original Dallas semiconductor parts even after 100Yonce accidentally put 5200 across 25V power rail and part survivedbut originals from Ebay oscillated in standby as Emitter follower and blew and I thought that transistors could not be that bad until opened one of them

author: james_s
author_rank: Super Contributor
timestamp: May 24, 2022, 06:08:53 am
content: Quote from: jfphp on May 23, 2022, 10:21:21 amThere are lots of perfectly fine Chinese parts. Most rare/hard to find parts from China are fake though, especially if the price is too good to be true. But if you need some 2N3904's or some other mundane part they're usually just fine.

author: max-bit
author_rank: Frequent Contributor
timestamp: May 24, 2022, 12:16:57 pm
content: And here Mr. Chinaman is trying to sell something like this:eBay auction: #https://www.ebay.com/itm/334432987035Hit 899 $Well, for $ 350 you can have an original evaluation board, not "I don't know what" Made in My Friend

author: MathWizard
author_rank: Super Contributor
timestamp: May 24, 2022, 06:56:16 pm
content: 1 of these days I need to go outside and burnout a few parts, just to see what they can handle vs sold as.I got some cheap mosfet's on ebay lately, they handle what I planned for them, but yeah, I have no reason to trust their ratings.

author: BrokenYugo
author_rank: Super Contributor
timestamp: May 24, 2022, 08:55:01 pm
content: Quote from: james_s on May 24, 2022, 06:08:53 amThat's how I look at it, if you're after the cheapest component of that type and package, the parts they remark to higher specs, you're probably getting something at least close enough. Though even then, unless you're after NLA stuff, it's often a better value to just keep a cart open at LCSC or whatever.

author: thm_w
author_rank: Super Contributor
timestamp: May 25, 2022, 12:39:05 am
content: Why would you buy from Ebay when genuine parts are available at reasonable prices from trusted suppliers:https://lcsc.com/product-detail/Bipolar-Transistors-BJT_STMicroelectronics-ST13009_C495229.htmlhttps://lcsc.com/product-detail/Bipolar-Transistors-BJT_Wuxi-China-Resources-Huajing-Microelectronics-3DD13009A8_C162358.htmlhttps://www.digikey.ca/en/products/detail/onsemi/FJP13009H2TU/1054789I would understand if the part is no longer sold, or if its very expensive, but this is a fairly generic high power TO220 NPN right?

author: slbender
author_rank: Regular Contributor
timestamp: May 25, 2022, 06:45:47 am
content: Quote from: Wallace Gasiewicz on May 23, 2022, 11:07:56 amIf you happened to make that determination by testing those FETs with the small Chinese <$20 testers, the tester may be falsely showing a bipolar part, as some microcontroller based testers do fail when the drain and source are electrically identical with respect to the gate. I have three of those tester boards all tend to say NPN when testing FETs.Steven

author: Paceguy
author_rank: Regular Contributor
timestamp: May 29, 2022, 04:10:15 am
content: I have learned the hard way and now buy the semiconductors and capacitors that I need for repairs from trusted reputable North American suppliers. Ebay is OK for things like switches, connectors, etc. I could be wrong, but I'm suspicious of ebay sellers who have what appears to be an infinite supply of semiconductors. Maybe they pick up the production rejects from a production company's dumpster and sell them.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: May 29, 2022, 10:54:57 am
content: Steven:I see your point, I have tested FETS with some testers and got dual diode as a readout.But these are not reading dual diode, And the transistors were tested on both modern testers and old time transistor FET testers and also show high emitter to collector resistance value.Also, I have used about 5 of these "fake FETs" in NPN transistor applications in repairs.. They work fine as NPN transistors.Therefore, I think they are intentionally mislabeled NPN transistorsWally

author: wraper
author_rank: Unknown
timestamp: May 29, 2022, 11:13:20 am
content: Quote from: Wallace Gasiewicz on May 29, 2022, 10:54:57 amBJT reads as dual diode when tested with multimeter in diode mode. Which is exactly how you should check them. Instead of attaching to a magic box and trusting what it guesses.

author: wraper
author_rank: Unknown
timestamp: May 29, 2022, 11:17:05 am
content: Quote from: Wallace Gasiewicz on May 29, 2022, 10:54:57 amIf BJT is used as a switch, N-channel MOSFET in many cases will work just fine instead of NPN BJT.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: May 29, 2022, 11:58:42 am
content: wraper:I understand that.I almost always check BJT with the diode mode first. FETs also. Saves a lot of time. Quite useful in evaluating components while on the board.Just saying that one tester identifies some FETs as FETS and some as dual diodes.These components were supposed to be FETs not MOSFETsThey "self identified" as NPN on multiple testers.Yes MOSFETS make good switches. Have used enhancement MOSFETS in place of switching transistors,

author: madires
author_rank: Super Contributor
timestamp: May 29, 2022, 12:09:56 pm
content: "Genuine or fake RF output transistors?"

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: May 29, 2022, 12:39:59 pm
content: Until Huagao, all 1969 clones were bad. I did not see one that worked, nor heard of one that worked. Maybe there were good ones, but I I have not come across a good one until Huagao. They would blow after being keyed up once or twice or at a max of three times. Just terrible.Huagao is now making good 1969 replacements. Quite reasonable pricing. There is no other source that I can find for these transistors, no longer made by original manufacturer.They also make other replacements including the elusive MRF 485, which I have not tried.And to think I did all those MOSFET conversions... no longer necessary

author: madires
author_rank: Super Contributor
timestamp: May 29, 2022, 01:16:35 pm
content: Quote from: slbender on May 25, 2022, 06:45:47 amBoth OSHW firmwares (k & m) detect JFETs with symmetric source and drain (it's also shown on the display). Very old firmware versions have a problem detecting a JFET with a low I_DSS (thinking it's a Germanium BJT).

author: madires
author_rank: Super Contributor
timestamp: May 29, 2022, 01:33:58 pm
content: Quote from: Wallace Gasiewicz on May 29, 2022, 10:54:57 amYep, it's intentional. I know of a few hobbyists who bought n-ch JFETs and got NPNs. It's still happening.