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Old 28th October 2012, 12:09 AM   #31
DaveG is offline DaveG  United States
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I still had the parts taped to a piece of paper, so here are a few photos. These were taken hand held with an old 4MP Sony shooting through the eye piece of a 20 power loupe, shimmed up with business cards to get the focal distance right. So it popped apart quite clean when slightly over heated.
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File Type: jpg J202_4web.jpg (473.2 KB, 105 views)
File Type: jpg J202_5web.jpg (709.5 KB, 102 views)
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Old 28th October 2012, 02:38 AM   #32
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Jitter, I don't know exactly. But the more certain that I am that these are not Toshiba the stronger my response will be... in various regards.

One supplier has agreed to take back one batch back, it remains to be seen if I will get anything back after I send it overseas.

I had ordered from a few suppliers figuring that they all wouldn't have bogus parts... ha ha.



DaveG, looks good. I've tried to crack a few, the results were not as good as yours. I may try some external heat and then a crack... what I saw through my stereo inspection microscope was a square blob that did not reveal any discernible surface characteristics that could be identified as one type of die layout or another... reasonably confounding in fact.

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Old 2nd November 2012, 06:47 PM   #33
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Here's the problem with the crack in the vise to open - the die surface is shattered. Apparently the epoxy is tenacious.

This one was with some significant heating first... propane torch... then a crack.

maybe next time I will apply excess heat to the pins, but I suspect that will pull the die off the flat copper area inside the package.

_-_-
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Old 16th November 2012, 04:14 PM   #34
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Well, I have a TO-92 case that so far I have soaked in room temp (RT) methanol, DMSO, Toluene, Chloroform, Acetone, DMF, Octadecene and water (because why not). Nothing so far has shown any signs of working. I'm debating boiling DMSO, if that doesn't work then I'm thinking agua regia next
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Old 16th November 2012, 06:02 PM   #35
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A member emailed me with pix showing that the "2SJ74" being sold are re-badged Fairchild parts. On some of his batch the Fairchild markings were not fully removed! Quite obvious.

Bogus parts.

Arrrgh!

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Old 16th November 2012, 06:05 PM   #36
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Default bogus 2SJ74 from asia

Here's what my curve tracer showed.

Identical settings, btw...


the curvy ones are the bogus parts.
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File Type: jpg ASIA SOURCE-2SJ74.jpg (324.9 KB, 13 views)
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