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Old 11th January 2008, 04:26 PM   #1
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Default ### 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 ?

greetings

dirk
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Old 11th January 2008, 04:35 PM   #2
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If it can make you a bit happy, I think most of us have some time have bougth counterfeits
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Old 11th January 2008, 05:06 PM   #3
ilimzn is offline ilimzn  Croatia
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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.
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Old 11th January 2008, 06:04 PM   #4
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@ACD :

Sry but this dont make me a bit happy

@ilimzn

here is the photo from the broken Transis. The die is 6*6 mm. There are this transis for trash or not ?

Dirk
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Old 11th January 2008, 07:13 PM   #5
wg_ski is offline wg_ski  United States
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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.
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Old 11th January 2008, 07:20 PM   #6
Nordic is offline Nordic  South Africa
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ISC make good quality parts, not fake, just not original manufacturer....
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Old 11th January 2008, 07:40 PM   #7
Eva is offline Eva  Spain
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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:
http://sound.westhost.com/fake/counterfeit-p2.htm

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.
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Old 11th January 2008, 07:55 PM   #8
Nordic is offline Nordic  South Africa
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Quote:
Originally posted by Eva

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.

Agreed... my thoughts too.
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Old 11th January 2008, 10:10 PM   #9
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but then only the 2922 is the problem. Because the 1216 look like ok when the company ISC makes normaly good parts.

Has anyone a little circuit how i can test the 2922 for the SOA ? Or other ideas how i can test the max power of this Trans ?
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Old 12th January 2008, 01:54 AM   #10
eyoung is offline eyoung  United States
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hello again...

Try Mr. Pass' website or Mr. Leach's both have tons of good basic info about transistors. As a rule of thumb you should always test(match) transistors to eliminate problems down the road.


Good Evening as always,
Elwood
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