### Counterfeit transistors

Hi all,

i have purchase from a german company a lot of 2sc2922 and 2sa1216 transistors. the producer is ISC (http://www.iscsemi.cn/).

but the 2SC2922 looks not real and original !

When you look on photo the surface of all 2SC2922 are have
sharpening traces on the surface. It looks like, that all 2922 are get a new label.. The 2SA1216 are smooth like a baby's bottom.

The metalplate of the 2922 are different then the 1216. The Plate of the 1216 has corners cut off from 45 deg but the corners of metalplate from the 2922 are rounded. Then the plate of the 1216 are polished and smooth. from the 2922 are a little bit rougher.

then the font of the labelprint are different. Look on picture isc2.jpg. The font of the labelprint from 1216 are bigger then the print on the 2922 and its a little crooked.

Know everyone about ISC and hear about counterfeit transistors of this company ?




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Since only Allegro/Sanken make these transistors, the ones you have are most certainly fakes (both types). This is not to say that they are non-functional, but the possibility that they are not very useful (or even useless) is high. I would suggest 'dissasembling' one of each (vise and hammer usually works), and have a look what is inside. If you find anythng smaller than about 6x6mm silicon crystal, I'm sorry to say that they are only fit to be thrown into the trash.
Looks a little bigger than a 2N3055 to me. It may be an attempt at a decent replica. "Real fakes" have obvious crap in them. There are second-source suppilers turning out old obsolete On/Motorola parts as well. They're not always complete junk - even if not up to original standards. Try a pair out on normal operating voltage and load impedance and see if they hold and see if several units match well.
These look like conventional Sanken fakes but with a slightly bigger die size.

Check this page to see the internal layout of genuine Sanken MT200:

Do your best to get a refund and warn other customers. The transistors that you bought are very far from genuine part perfromance.

These transisotrs are not necesarily made by ISC, they could be intentionally labeled ISC by some competitor to damage company reputation. Chinese electronic component market is really unfair and lacks any ethics.
Hi Dirk,
keep us informed which supplier it is and how he reacts when you declare those parts as useless.

With Reichelt.de for instance, I phoned to ask which bipolars are original and which are third party. I've just to check if their answers are consistent with the parts I got.

Hi all,

i have send to ISC a mail with photo of the transistors. This is the Answer :

Dear Dirk,

The transistors you show to us is real our products.
You needn't return them back to Reichelt.
Maybe the rougher surface of this transistor is caused by transporting many times.
We have not done the business with this customer named Reichelt.
Maybe he bought this transistors from our other customers.
Thanks for your information.
Any more questions, please feel free to contact with me.

Yours sincerely,
Miss Lynn for

but the problem is, that the rough surface dont come from transporting. Because the rough is only on the place were the printed font is. but on the edge there is nothing.

And when is wish with a white wet towel on the 2922, the towel is after then black. make i the same over the 1216, the towel remains white.

the surface of the 2922 are defintifly worked with abrasive paper.

Anyone a idea why ISC should be worked with abrasive paper over the 2922 (not only by one, i have purchase 15 of 2922 and thats by all!)?
Transistor numbers are not exclusive registered trademarks, so there are many suppliers for, e.g. 2N3055, or IRF610, or OP37, or LM317, ..... etc. You cannot call them fakes unless they printed someone else's (e.g. Sanken) logo on top of the transistor. They did not in your case, so you can at best call them cheap imitations. But e.g. Samsung also makes IRF610, and I would not call Samsung products cheap imitations.

I ordered once 2 of those transistors for fun from Reichelt as well, knowing the lower price probably meant not Sanken. You could also order BJTs like MJ15003 from Reichelt, and they offer two types -- ones specifically from Onsemi (and more expensive) and others. I guess we just have to be on the watch out, not only on the number but also manufacturer and price.

You also cannot accuse Reichelt of cheating, as they never say on their catalog that they are from a specific manufacturer. You can, e.g. order 2SK170s from them but they come as CSK170, i.e. not Toshiba but equivalents.

What is honest about Reichelt is that before you order, you can send them a email asking specifically what they have on stock now and from which manufacturer. E.g. I did order genuine 2SK1058s from them and they did tell beforehand that they were from Renesas.

Doesn't make you happier, but perhaps wiser. (I leanrt my lessons as well.) And maybe you could try to return them to Reichelt ??

Hi patrick,

1. i dont say, that i purchase the transistors from reichelt ! This stand in the Answer from ISC, is not from me.

2. When you look and read this thread completly, you will see that Onvinyl talk about reichelt at first, not me . i dont say anything about reichelt !

3. I know that this Transistors are not from Sanken. i know befor i buy this transistors, that it give 3 company´s there are made 2sa1216/2sc2922 (Sanken, wingshing and mospec)

4. i know that reichelt dont cheat, because reichelt get this transistors from a other company and i never say this. Read my question and answers.

5. bevor you write a answer, how the last answer from you, read first what i wrote.

i only ask, somebody whether know ISC and heard that give Counterfeit transistors from this company. Nobody talk about reichelt. i´m not, only you !


P.S.: auf gut deutsch, erst lesen dann antworten !! First read, then answer !
Thats all no problem patrick.

And i have no problem, when the transis comes from isc, when there are ok. And i have no problem with reichelt, there have a good service and i´m over 10 years a good customer.

My problem is, why should ISC wearing down the old Label and print a new label on the 2922.

When you look on the new Photo you can see the sharpening traces on the surface of the 2922. And this don´t come from transport. I wish with a little rag and Isoprophylalcohol over it and the result is that the rag from 2922 is black, from 1216 is white.

When one or two of the 2922 has this problem, ok, with that i can living, but all of the 15 of the 2SC2922 that i bought have this sharpening traces on it.

And that is my problem.



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Well, it's possible that they are genuine ISC parts ... even the abraded ones.

When transistors in particular are manufactured, they are often made to a batch specification ... and then they get labeled with the type / part number. Sometimes the type/part number is a general part number like the part numbers you show. Sometimes the type / part number is an OEM specific number ... like TR29.

It's totally possible that an OEM ordered these transistors as an OEM specific lot, and then cancelled the order. That leaves the manufacturer with a lot of expensive packaged transistors to deal with. It is probably too costly to throw them away, so they relabel them. Some makers aren't too clever when they do this ... some put a layer of paint over the old label, and print a new one ... some sand the surface as you see with yours.

What you really need to do is put these through a test to see if their specs are close to the brand name and then soak test (a long test) them at load for a couple days (i.e. near their ratings). If the specs are close and they soak test at load OK, then use them as what they are labelled.

If in the soak test they die quickly, then you know they are NOT what they claim to be.

There are fake transistors out there that are NOT complete rip-offs ... some actually perform at or close to specs.

While they aren't the original named manufacturer (Sanken?), they may be made by a reputable copy maker (ISC) and just be relabels.

Testing is the only way to find out if they're usable which is really the only important thing. If it's a usable transistor then, hey, nothing lost. They may not be top grade, but they work.
Judging by what I have read in this thread, ISC knows no ethics and is producing useless junk too, like many Chinese companies.

The transistors from your pictures are manufactured with fake-grade quality, with the white silicone goo that you will never see in a genuine part, the fake heat spreader (originals have an extra thermal pad) and a die half the size of the original.

Try to return this junk and get a refund or you will see these transistors blowing in your amplifiers for no apparent reason.