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Counterfeit 2SC2240

Discussion in 'Solid State' started by tarior, Mar 2, 2010.

  1. tarior

    tarior Dirty pool, old man?

    Messages:
    4,994
    Location:
    Kelso, Washington
    I was working on a customer's Marantz 140 today, and I wanted to replace the differntial input pair with some 2SC2240 transistors. I got to looking at what I had, and they were very different from each other.
    The one on the right is a genuine Toshiba part from Mouser. The one on the left is an apparent fake, I'm not sure where it came from. It's pretty sad when the Chinese are counterfeiting 20 cent transistors.
     

    Attached Files:

  2. Stuart Pedaso

    Stuart Pedaso In too deep Subscriber

    Messages:
    1,115
    Location:
    Solano County
    Care to crack a couple open to compare dies?
     
  3. tarior

    tarior Dirty pool, old man?

    Messages:
    4,994
    Location:
    Kelso, Washington
    The dies appear to be similar sized, the pinout is NOT correct. It really pains me to wreck a perfectly good transistor, BTW.:sigh:

    Again, Toshiba part on the right, fake on the left. It's hard to tell without a magnifier, but the Toshiba is better quality. Note the discoloration about the die on the fake part.
     

    Attached Files:

  4. glen65

    glen65 Member

    Messages:
    4,262
    Location:
    Richland county, Ohio
    It appears that one is also a different pin out.
     
  5. avionic

    avionic " Black Knights" Subscriber

    Messages:
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    Fort Dodge, Iowa cornfield
     
  6. ecluser

    ecluser Super Member

    Messages:
    3,219
    When we want a 2SC2240, we don't just want a transistor that work in a circuit, we want a low noise transistor.

    Yes, the Chinese are counterfeiting 20 cent transistors.


    I can send you a 2SC2240 that will not work. I bought six 2SC2240 from a local parts store (by chance they had only 6 in their stock!) and when I tried to match them, I couldn't measure their hFE, no matter what pin-out I tried.

    I put them on my beloved curve tracer and it turns out that all of them were very bad PNPs !!!

    Since this misadventure, I never buy transistors from this store (ÉlectroMike in Québec city).

    In the picture on the first post, we can see that the left one is labeled c2240 Y. As I know, the hFE classification for the 2SC2240 is GR or BL. I didn't check all the datasheets for the 2SC2240 to see if some manufacturers use the Y classification...
     
  7. avionic

    avionic " Black Knights" Subscriber

    Messages:
    27,678
    Location:
    Fort Dodge, Iowa cornfield
    I get all my japanese tranny's at BDent haven't had a lick of problems. But I usuaully match up the suffix codes as well BL,GR. etc. BD has a very large selection. They also have a $15 min. order so I usually end up buying extra quantities..
    http://www.bdent.com/
     
    Last edited: Mar 2, 2010
  8. glen65

    glen65 Member

    Messages:
    4,262
    Location:
    Richland county, Ohio
    PNP?
    Wow..I guess they did screw them up.
    Don't know if you would be interested but Fairchild make
    a direct low noise replacement for these, KSC1845.
    http://www.fairchildsemi.com/ds/KS/KSC1845.pdf
    You could probably get some samples and give them a shot.

    So far Ive had no problems with them myself.
     
  9. avionic

    avionic " Black Knights" Subscriber

    Messages:
    27,678
    Location:
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    I only see GR and BL...
     
    Last edited: Mar 2, 2010
  10. tarior

    tarior Dirty pool, old man?

    Messages:
    4,994
    Location:
    Kelso, Washington
    Like ecluser said, I want the 2240 that Toshiba shows a datasheet for. If the pinout is different than Toshiba's datasheet, it's phony part as far as I'm concerned. Furthermore, what are the chances that these things are going to meet the proper noise, current, voltage and cutoff specs? I'm betting slim to none. They aren't identical or interchangeable, and I'm sure as heck not gonna stake my reputation on them.

    As an example on the same topic, I keep Toshiba 2SC2383 on hand for a good all around replacement NPN. I've also bought Fairchild KSC2383, and you know what? Their spec sheet is practically identical to Toshiba's. Pinout, current, voltage, everything. In this case, these are basically the same transistor from two different mfrs.

    A tech can do a hundred perfect jobs in row, but the one people will talk about is the one that turned to shit because of bad parts.
     
  11. tarior

    tarior Dirty pool, old man?

    Messages:
    4,994
    Location:
    Kelso, Washington
    I actually ended up using KSC1845 in this case, but it only has half the current capacity of 2SC2240. I'm ordering new Toshiba 2SC2240s from Mouser in the morning.
     
  12. dr*audio

    dr*audio Fish fingers and custard! Subscriber

    Messages:
    17,643
    Location:
    Cleveland, Ohio
    I bought my 2SC2240's from MCM Electronics, and they have BL on them. The HFE measures around 380.
     
  13. avionic

    avionic " Black Knights" Subscriber

    Messages:
    27,678
    Location:
    Fort Dodge, Iowa cornfield
    A noisy transistor I would not consider working... I was just stating that there are other companys legit or not unloading these on the market.And obviously there is junk out there.
     
  14. tarior

    tarior Dirty pool, old man?

    Messages:
    4,994
    Location:
    Kelso, Washington
    Most likely the real deal, and you can tell by the lettering.
     
  15. tarior

    tarior Dirty pool, old man?

    Messages:
    4,994
    Location:
    Kelso, Washington
    With all due respect to you, in this case if it's not Toshiba, it's a junk fake as far as I'm concerned.
     
  16. avionic

    avionic " Black Knights" Subscriber

    Messages:
    27,678
    Location:
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    Concur...:yes:
     
  17. glen65

    glen65 Member

    Messages:
    4,262
    Location:
    Richland county, Ohio
    I'm not sure if I've used those before. But I like to keep something
    on hand that will replace a number of devices.

    You got it,
    All it takes is one mistake and all of the sudden your work sucks.
    I had one amp that gave out. Fortunately it was during the time
    I was stress testing it on the bench. Come to find out that two
    of the outputs were counterfeit. I bought them from some place
    called Audio lab Of GA.

    You wont have any problem with those guys.
     
    Last edited: Mar 3, 2010
  18. dr*audio

    dr*audio Fish fingers and custard! Subscriber

    Messages:
    17,643
    Location:
    Cleveland, Ohio
    Glen, thanks for the heads up on Audiolab of Georgia. I have ordered parts from them before (IC's) and now I will use them as a last resort, if at all.
     
  19. tarior

    tarior Dirty pool, old man?

    Messages:
    4,994
    Location:
    Kelso, Washington
    Hmmm...I've always heard good things about Audiolab of GA, and have bought from them in the past. I sure hope it was a fluke.
     
  20. glen65

    glen65 Member

    Messages:
    4,262
    Location:
    Richland county, Ohio
    Ive seen the reports go both ways.
    Their service (at least for me) was fine.
    They even took some semis in on exchange once.
    However their product was another matter.
    I ordered product from them more than once
    because they had something the others didn't
    at the time. It turned out to be a bad move on my part.
    So I have completely crossed them off my list.
     

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