"Fake" 2n5457

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tabbycat
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Post by tabbycat »

Blitz Krieg wrote:Parts are made. measured. Binned. and then labeled. Why would they get labeled if they fell so far out of the specified parameters for said part?

most big companies will destroy inferior product so that it doesn't end up on the marketplace and harm their most valuable asset - their reputation.

maybe the parts get tested again after labeling? someone walked out of the wharehouse with a box full of rejects that were in the garbage?
the most important thing to any company is a healthy bottom line, reputation is always secondary to that, for without a healthy bottom line the company will go bankrupt and the reputation means nothing. machiavelli has a chapter on that kind of thing in 'the prince'.

so mictester's comment makes most sense. only attaching their brandname to the good stuff, and passing the rest on (without a brand name) for anything they can get for it, would be the most logical and responsible (in a business sense) move.

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Post by JudgeMingus »

..Except that it encourages a race to the bottom in price: as no device can then be guaranteed to be of its 'rated' value, all devices must then be treated as suspect and the price (and margins) fall.

This is very bad for the bottom line in the longer term, so the question is really whether the manufacturer's management care about anything other than short-term gains (maybe not)

My workplace has been hit by failing VoIP phones - the original batch were un-knowingly* built with counterfeit (under-specced) capacitors which then failed due to continuous exposure to over-voltage - the phones stop working and light up like a Christmas tree!
Hundreds have gone back from us, and no doubt other customers have been returning many more.
I bet the manufacturer of the phones is not happy with their capacitor supplier!


* Or so the manufacturer says.

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Post by tabbycat »

JudgeMingus wrote:..Except that it encourages a race to the bottom in price: as no device can then be guaranteed to be of its 'rated' value, all devices must then be treated as suspect and the price (and margins) fall.
not sure what you mean. why could no device be guaranteed of its rated value?

as an example, wang co (made up name) is a prestige ic supplier providing 'grade a' ics for prestige electrical manufacturers.

wang co produces 100 ics.

70 meet its highest spec. these get stamped 'wang co approved' and passed on to prestige electrical suppliers.

30 don't meet its highest spec (broader tolerances) but are still useful in some less demanding applications.
they don't get stamped 'wang co approved' but are left blank and passed on at an appropriate discount to any manufacturer who will take them, along with the information about the tolerances being broader.
as long as they are providing the info to the buyer about the spec being broader they are behaving entirely honourably and conducting good business. their reputation, bottom line and margins are safe.

the problem comes when a rogue company 'ping co' (made up name) tries to be clever, thinks it can make a quick buck, and installs these lower tolerance ics in devices which demand the highest spec components, in the full knowledge that they are using ics unfit for this purpose.
these devices either don't work or more likely work for a while and then fail quickly. ping co (not wang co) are behaving dishonourably and conducting bad business, and their reputation, bottom line and margins are likely to suffer.
the only way they can conduct this sort of business and make money is if they disappear before the returns hit the fan.

so re "no device can then be guaranteed to be of its 'rated' value, all devices must then be treated as suspect", it's more a case that any item fitted with a 'wang co approved' ic can be trusted, whereas others may be suspected.

which actually works in wang co's favour. as manufacturers and customers have to accept that if they want to real thing they will have to pay a premium for it.

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Post by mictester »

A designer friend of mine had huge problems with exploding power supplies in TV sets that he'd designed. The company had decided to cut costs and source their parts from a company in Vietnam (not a country known for its high volume, high quality component manufacturing). The rectifier diodes, series pass regulator transistors and the smoothing capacitors all turned out to be sub-standard, though "correctly" marked. Some of the explosions caused further fires, and the manufacturer was held liable in some cases..... Saving about 35% on the parts cost the company huge amounts in reparations and even more in damaged reputation!

The problem that we have - buying small quantities of parts for our personal use - is that it is seldom economical for a company to sell just 10 or 20 of a part. If you're ordering just one IC, the situation is even worse! The suppliers of retail components to the amateur market have to tread a fine line between losing money and exploiting their customers.

Companies like "Maplin" in the UK and "Mouser" in the USA really exploit the small consumer. Maplin buy (say) 1 million 10k ¼W resistors for £200 (not an uncommon price in the bulk component market) and then sell them at 10p each - that's 9.98p profit per component. Even if they bought them from a supplier like Farnell, they'd get them for 0.2p each, still giving a mark-up of 9.8p per part.... This really is profiteering - especially when they have a "minimum order" of £8 - £10. The more capitalistic amongst us would say that they're "charging what the market will stand", but even I would say that this is a rip-off. It's actually cheaper (and quicker delivery) for me to order 1000 parts from Hungary or Singapore than it is to buy 10 to 20 of the same part from Maplin!

I've been examining the economics of opening a component store in the UK - by post only to begin with, but with a shop front in the second or third year. If there was a sensible range of parts - not just for guitar effects and amplifiers, but for model-making, radio or computer construction and a few other electronics-related hobbies - and with reasonably well-paid staff who knew about and understood what they were selling, it can be done. The effort involved would be great, and the initial financial outlay would be quite large, but if done properly it would make money without robbing the purchasers. If done well enough, it should put Maplin out of business in a year or two! I would be prepared to stock some of the more exotic components sourced from the Far East, but would ensure that they were thoroughly tested before being made available for sale. These tests would make them slightly more expensive than buying unknown, untested parts from Ebay, but it would eliminate the risk for the customer.

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Post by tube-exorcist »

So folks, here is the truth about "tested" components and how testing is done. Did you really believe that every individual part will be tested ? Sorry, no bonus..... at the end of the day a sample batch will be taken, the "AQL-rate" will be determined and if it is too high, the complete production run (of the day) will be dumped (and maybe land on the black market).
The acceptable quality limit (AQL) is the worst tolerable process average (mean) in percentage or ratio that is still considered acceptable;.....

..... An acceptable quality level is a test and/or inspection standard that prescribes the range of the number of defective components that is considered acceptable when random sampling those components during an inspection. .....
https://en.wikipedia.org/wiki/Acceptable_quality_limit
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Post by chicago_mike »

All the IPS screens that Apple rejects from their cinema display go to chinese eBay manufacturers...all those 27" tips screens you see for like 199 on eBay with goofy ass names. Those are apple displays, apple just was like...nah, not good enough for us....those snooty fuckers. :mrgreen:
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Post by matt239 »

OK, so some folks here admit that there are fake parts all over the place, that suppliers and manufacturers have to have massive programs in place to prevent counterfeit parts, but say:
"but there COULDN'T be fake JFETs, because they're so cheap."
Why would we doubt JFETs would be faked?

1st: of all, what J0K3RX said:
J0K3RX wrote: If there is no money in re-marking these parts because they are so cheap then why would they bother making them in the first place?"
... "These parts are all still in reels and on tape all facing the same direction... they are being fed back into the machines just like that and then packaged with their new identities... Probably takes very little time or effort to do this and then they can sell stock that would have otherwise sat in a warehouse for years. I am sure they can do this with ease and probably have entire plants that do nothing but re-mark components.
... The list is endless..
http://www.npr.org/templates/story/stor ... d=11656278
2nd: Consider, a penny X 10,000 is worth a lot more in some neighborhoods in China, than it is in the West.

3rd: Not to cast aspersions against the Chinese people & culture, but we can understand that AT THIS MOMENT IN HISTORY, IT'S THE "WILD WEST", OR EAST.
- Fabulous wealth, enormous energy, & potential, but also crushing poverty, inequality, & oppression. and a SYSTEM that is ABSOLUTELY THOROUGHLY CORRUPT, top to bottom.
ANYTHING GOES.

4th: "Why would you bother to fake something so cheap, rather than something more expensive/worthwhile?" - Easy: Crime of OPPORTUNITY. You, or your cousin or uncle didn't happen to work at a Foxcon?Apple, TV factory, you worked at the transistor plant.
These transistors could have been "found" - traded-for, acquired, for nearly nothing, same with the machines to print on them. - Why not run a few batches and SEE how many you can sell?

5th: Isn't it proven by actual experience now? In this thread, one poster said Fairchild has confirmed it, and another said he tested a batch and found them to be NPN bi-polar.
and read the tales here:
https://www.diystompboxes.com/smfforum/ ... =97600.120

So yes, I THINK WE CAN SAY THERE ARE FAKES OUT THERE.

The question is made more complex because legit JFETs vary widely anyway.
(but that doesn't mean there are no fakes, or sometimes just parts WAY off spec, that got labeled as OK by someone..)
So the real question is how to test any JFET to make sure it will function in your circuit.

P.S. I bought a batch of 2N5457s from Hong Kong when we first found out through-hole JFETs were being obsoleted, before Mouser was out, but had raised the price & minimum order, so 2 or 3 years ago, I don't remember exactly.
- I don't remember the name of the seller. I MIGHT be able to find it. It was a large seller with huge amount of parts and a good rating. I also bought a bunch of 5088s
- I have not used any yet.

How likely are these to be fake? - Had that started (with JFETs) yet?

How can I test them?
I know we have the one test for "matching" JFETs, but I have never done it yet. Anything else?

Or shall I just drop them in some circuits and see if they work?

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Post by idy »

I like that question, or this one: what kind of test will show whether a transistor is bipolar or FET?
The FET doesn' test like pair of diodes? It conducts "more ways?"

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Post by Dirk_Hendrik »

matt239 wrote: How can I test them?
Building em in a circuit and see if they work will, in many cases, result in a full positive.

So how to test em?
Take the datasheet of the original.
Look op all parameters and curves for the component and build test setup(s) that can verify these parameters and allow you to duplicate these curves.

If all turns out the same, your component is not a fake. Do not forget to check for manufacturer specified tolerances AND (!) make sure you perform these measurements on some parts of which you know for sure they're genuine as well. You may be in for surprises.

And, if you think that's a lot of work, why do you think the companies that do component counterfeit research cost so much?
Sorry. Plain out of planes.

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Post by Pruttelherrie »

matt239 wrote: How can I test them?
Buy one of these: https://www.ebay.com/itm/12864-GM328-Tr ... 1646342507

But beware: the original tester was developed by a german electronics enthousiast who might just happen to be an engineer at VW. He could have included a hidden functionality that detects that you're trying to measure a re-labeled bipolar and return readings that tell you it's a JFET :D

(original project in german here: http://www.mikrocontroller.net/articles ... stortester)

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Post by matt239 »

idy wrote:I like that question, or this one: what kind of test will show whether a transistor is bipolar or FET?
The FET doesn' test like pair of diodes? It conducts "more ways?"
Well they're all still transistors,
but all transistors don't behave exactly the same, otherwise WHY MAKE DIFFERENT KINDS? & why publish DATA SHEETS?

I have nothing against BJTs, for the things they are good at.
I'm not just worried about mojo here.
- If we were talking about a one-transistor boost, or something, and you put in a BJT instead of JFET, and it works, and you can't tell the difference... well OK then..

but has anybody here had success using random BJTs as VCRs in a PHASER, or an ORANGE SQUEEZER?
Dirk_Hendrik wrote: Building em in a circuit and see if they work will, in many cases, result in a full positive.
I don't require devices to be perfect, as long as I can get them to work, or work with a few changes to resistor values..
If I can get the circuit to function CORRECTLY, then I'm willing to call it good & move on with life.

So I guess just sticking them in the circuit is probably an ok test..
I just don't want to spend a lot of time trying to figure out whether I made a wiring mistake, vs. the device is bad..

So if someone could say: "ok, test x-parameter, & y-parameter, and here's how you set up your test rig, do this for a dozen of your devices, & if they measure ok, then they are probably 2n5457s.." (Or at least JFETS!..)
- that would be awesome.
Last edited by matt239 on 09 Oct 2015, 23:49, edited 1 time in total.

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Post by mictester »

matt239 wrote: So if someone could say: "ok, test x-parameter, & y-parameter, and here's how you set up your test rig, do this for a dozen of your devices, & if they measure ok, then they are probably 2n5457s.."
- that would be awesome.
There are very cheap transistor tester kits from China. They're (mostly) very good - often as good as the "Atlas" testers, but only at about $15 - 20. They're easy to construct (if you can solder neatly) and they work well.
http://www.banggood.com/DIY-M12864-Grap ... 86954.html is really good. It also tests diodes, resistors, capacitors and inductors. If you buy the box to go with it, don't fit the ZIF socket - wire the inputs directly to the external sockets.
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Post by Dirk_Hendrik »

Those tester kits save so much ime it almost hurts.

Anyone remember the horrrible transistor tester on multimeters where the contacts were so deep in the socket one had to solder wires to the transistor legs in order to get em to make contact? After plugging and replugging to find out the pinning...
Sorry. Plain out of planes.

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Post by matt239 »

Thanks for the tester kit idea. - That would come in handy all the time.
I had thought of building one before, then forgot all about it. - Now I think I'll do it.

My 5457s look real. The printing looks more like the good ones in the photo on this thread.

Might need to test or match them anyway, just because: JFETs...

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Post by deltafred »

A build manual for the transistor tester kit is available here,
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Post by Ice-9 »

deltafred wrote:A build manual for the transistor tester kit is available here,
I have just had a look at that PDF :applause: Deltafred, but I did love/laugh at the bit which say "After all the welding jobs are complete........"

I have to say I have never needed to resort to welding a 1/4 Watt resistor in place but I would think I will give at a try next time, also when welding in Jfets or Cmos components I think gas welding might be preferred over electric arc welding so as not to damage these static sensitive components. :mrgreen: :thumbsup
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !

No silicon heaven ? preposterous ! Where would all the calculators go ?

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Post by deltafred »

A good example of "Chinglish".

My son is a translator working for an international company in in Spain. His was taken on to translate documents from Spanish to English but says proof reading (and correcting) those already in use will keep him busy for years.
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Post by mictester »

deltafred wrote:A good example of "Chinglish".
One of the funniest bits of Chinglish that I remember was in a manual for a mechanical digger. It kept making mention of the "water sheep". It took me nearly three pages to realise that they meant "hydraulic ram"! :lol:

A 1960s Sony tape recorder manual first showed pictures (and size details) of the tools that would be needed to work on the machine, and then gave a diagram of the deck plate, pointing out the positions of the screws that needed to be removed to open the deck panel. It asked you to "ceremonially disembowel with a screwdriver number 2" :applause:
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Post by Manfred »

Today I received a bunch of ten 2N5457 bought at Ebay.
A sales location in Germany was given, now comes the surprise: the tiny plastic bag is lettered with Chinese characters.
It seems to be a new trick for hidding the sales place.
I measured all and read values with few variations, but the mean value of the forward transconductance is noticeable higher than specified in the data sheet.
I read 20 Milliamps/Volt the range in the specifications is given from 1 to 5 Milliamps/Volt.
I made a Id/Vds curve trace, the curve deviates significantly too.
The question is, are those fakes or a sale of rejects?

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Post by modman »

Hey Manfred, do they perform as fets?
This discussion :beatdeadhorse: has been going on for so long that a few years back, I bought a bunch of FETs from various Chinese vendors on Ebay... just to test them. I decided to build extended version of the Minibooster as suggested by Paul C, using four FETs.
I cleaned up my sty yesterday, came across the fets, and now I cannot find them. But I remember throwing out the cardboard boxes they were in -- I may have to check the garbage in the morning. :roll: :lol: If I find them, I will send you some...

My transistor tester is an old PEAK DCA50e that cannot recognize FETs, but shows them as NPN with a gain of +900. But they all seemed to work in the Minibooster based circuit... Ok, went and found them in the trash. Luckily, we recycle and have a cardboard/paper bin.

They look fake as fuck!
IMG_2960.jpg
IMG_2955.jpg
IMG_2951.jpg
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