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Old 29th November 2012, 12:47 AM   #41
Zen Mod is offline Zen Mod  Serbia
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antoinel - don't be naive

fake parts are always cheapest ones in appropriate package

dual bjt instead of 2SJ109 or something like that

there are more than few threads on DiyA , discussing those things

there is no big philosophy about
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Old 29th November 2012, 12:51 AM   #42
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Quote:
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antoinel - don't be naive

fake parts are always cheapest ones in appropriate package

dual bjt instead of 2SJ109 or something like that

there are more than few threads on DiyA , discussing those things

there is no big philosophy about
Thanks Zen Mod. I'll search the threads for examples to get an insight into the minds of those who've done it.
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Old 29th November 2012, 12:56 AM   #43
qusp is offline qusp  Australia
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well I had some fake 2SC5200/2SA1943 which I put in a higher current super regulator to run at +/60, had +/-70V in and they failed open under load in a matter of seconds. replaced them thinking it was something I did, checked everything, replaced a few caps, reduced the Vout and Vin for a lower +/-35 with +/-42 in.... burned again
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Old 29th November 2012, 01:11 AM   #44
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My question will be selling "janeh2100" and "sharpseller2000" two vendors but the same person on Ebay (China).

Or they do not even know what they are selling, or will also be swindled by the mafias of transistors ....


My question:


------------
Dear janeh2100,

What is the value of IDSs fet. This is fet Original? Are you sure that this is not fake fet?

The letter J does not have the dash above ...

Ensure that it is original I buy 10, but if they do not Idss between 6mA and 12mA and transconductance of approximately 20mS, I will have to return them.

respects

---------------------------------

hello client,
to be honest, I'm not professional about this transaction, cannot 100% sure if it's original
my supplier just informed me it's J-FET, NOS Transistor, New, and in good working condition guarantee.
hope you can make sure before purchase
best regards,
Ari

E-mail : moonmai555@yahoo.com.cn
Phone Number: 086-755-25506967
working date: 9:00AM - 18:00PM , From Monday to Saturday
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Old 29th November 2012, 01:24 AM   #45
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Quote:
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well I had some fake 2SC5200/2SA1943 which I put in a higher current super regulator to run at +/60, had +/-70V in and they failed open under load in a matter of seconds. replaced them thinking it was something I did, checked everything, replaced a few caps, reduced the Vout and Vin for a lower +/-35 with +/-42 in.... burned again
The bjts were destined to fuse. In hind sight, what will you do today different to ensure the avalanche of damage past will never occur?
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Old 29th November 2012, 01:26 AM   #46
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I had oscillation problems on a part that otherwise tested ok using minimal initial testing. This was in direct comparison to known good parts. After inquiring further, I eventually ended up getting the manufacturer to check box and batch numbers. They were unable to correlate the info on the parts with their production records. I was a couple days from court. Seller finally refunded the transaction.
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Old 29th November 2012, 01:29 AM   #47
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Consider the possiblity of a part that is close in operation being rebranded as another, more attractive part. Functional, but not true to specs of desired parts. On some levels, it may test close normal specs. Many people would never go beyond this and accept any problems that occur as something else. I got lucky as well as having some good guidance from some friends
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Old 29th November 2012, 01:41 AM   #48
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Ahhh...as I though my posted make eveyone understanding in Chinese Business :-)
They lived with tear and their customer breath :-(

I hope this's the last time I paid to Chinese distributor
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Old 29th November 2012, 01:42 AM   #49
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Quote:
Originally Posted by buzzforb View Post
I had oscillation problems on a part that otherwise tested ok using minimal initial testing. This was in direct comparison to known good parts. After inquiring further, I eventually ended up getting the manufacturer to check box and batch numbers. They were unable to correlate the info on the parts with their production records. I was a couple days from court. Seller finally refunded the transaction.
Thanks buzzforb. You have several important steps in a great process to deal with fakes.
  • Put the part in test circuit.
  • It misbehaved
  • Talked to the manufacturer of authentic parts
  • It compared fake with authentic
  • Got an iron clad proof of a misfit part
  • Confronted the seller with this evidence
  • Recovered money from seller
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Old 29th November 2012, 02:00 AM   #50
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Ha. You make it sound so easy.
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