Author Topic: How often do you see fake chips?  (Read 2401 times)

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Offline T3sl4co1l

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Re: How often do you see fake chips?
« Reply #25 on: September 17, 2019, 01:34:54 am »
That part was clearly desoldered (salvaged).

(Unless you took the picture after testing it, in which case that's technically correct but it's your own doing, so nevermind?...)

The white bar [not] over the dimple is amusing, surely no real manufacturer does that (I don't know of any examples of this?).

LM358?

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Offline OwO

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Re: How often do you see fake chips?
« Reply #26 on: September 17, 2019, 03:45:50 am »
And if you do the refund, you are no longer allowed to leave a feedback, that's why eBay fake sellers can keep 100% positive reviews.
Maybe that's why I had a bad experience with ebay but much better with aliexpress. As long as you stick to rating > 98% on aliexpress usually you don't get duds, but op amps are just one of the things you shouldn't buy from the marketplace and expect it to be genuine. Actually I don't expect anything I buy to be genuine, I just expect them to mostly perform within spec and it turns out to be true for most parts. Linear regulators and op amps are the exception.
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Offline thm_w

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Re: How often do you see fake chips?
« Reply #27 on: September 17, 2019, 10:21:19 pm »
And if you do the refund, you are no longer allowed to leave a feedback, that's why eBay fake sellers can keep 100% positive reviews.

Didn't know that about ebay. aliexpress lets you get a refund and leave a negative review, thankfully.

That part was clearly desoldered (salvaged).
(Unless you took the picture after testing it, in which case that's technically correct but it's your own doing, so nevermind?...)
The white bar [not] over the dimple is amusing, surely no real manufacturer does that (I don't know of any examples of this?).

LM358?

Tim

Sorry should have specified this was after I desoldered it from the test board. You are probably right that its a LM358 or something close.
Although I'm going to try my luck with a few salvaged parts because: it seems faking a used part would be a poor choice as you'd get more money for one sold as "new", and salvaged parts are sometimes ridiculously cheap say 10x less cost than new. Even if 8 out of 10 work I would be happy, as long as its not hard to validate their performance.
We recycle a lot of electronics and 99% of the ICs on the board are working well.

Maybe that's why I had a bad experience with ebay but much better with aliexpress. As long as you stick to rating > 98% on aliexpress usually you don't get duds, but op amps are just one of the things you shouldn't buy from the marketplace and expect it to be genuine. Actually I don't expect anything I buy to be genuine, I just expect them to mostly perform within spec and it turns out to be true for most parts. Linear regulators and op amps are the exception.

Agreed.
Any opamps/regulators I buy will be from LCSC/digikey unless its some unique package/pinout/function.
 

Offline thm_w

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Re: How often do you see fake chips?
« Reply #28 on: September 28, 2019, 12:40:25 am »
The STM32F030 I bought from the same seller are counterfeit as well. The top is sanded down and re-laser marked. They also laser marked into the pin 1 marker which no one really does?
57 people buy a microcontroller and never test it   :'(

https://www.aliexpress.com/item/32802747332.html

edit: seller had another listing for 100pc and there was one review claiming they tested it OK. So now I'm starting to doubt myself. But some of the ESD diodes are different readings, so I'm 99% sure there are differences in the chips..
« Last Edit: October 08, 2019, 12:51:36 am by thm_w »
 

Offline HHaase

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Re: How often do you see fake chips?
« Reply #29 on: October 05, 2019, 01:14:48 pm »
With linear regulators it's just rampant now. I can't remember the last time I've seen anything in a TO-323 package that wasn't counterfeit.  I used to use a lot of LM323's, 78H05's and as replacement parts in pinball machines.  Anything available now is usually the cheapest 5v regulator die available, stuffed into the big metal housings, with just some thermal glue holding it down inside the case.  Assuming it even works, you're lucky to get an amp of current, where the genuine parts are supposed to be 3A to 5A depending on the part number.  Any time you see blue insulators around the legs on something with that style package, run away and don't look back.
 

Online wraper

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Re: How often do you see fake chips?
« Reply #30 on: October 05, 2019, 01:22:52 pm »
With linear regulators it's just rampant now. I can't remember the last time I've seen anything in a TO-323 package that wasn't counterfeit.  I used to use a lot of LM323's, 78H05's and as replacement parts in pinball machines.  Anything available now is usually the cheapest 5v regulator die available, stuffed into the big metal housings, with just some thermal glue holding it down inside the case.  Assuming it even works, you're lucky to get an amp of current, where the genuine parts are supposed to be 3A to 5A depending on the part number.  Any time you see blue insulators around the legs on something with that style package, run away and don't look back.
It is no surprise when buying no longer produced parts at shady places for low price. If there is no such part, they will 'produce' it for you. If you want genuine 78H05, look for NOS and be ready to pay $10/piece. Not $5/10 pieces. Also if you don't want to use modern parts in different package, thus using bodge wires, you can do this way https://www.ezsbc.com/index.php/featured-products-list-home-page/psu7.html#.XZia-kYzbuo/
« Last Edit: October 05, 2019, 01:32:24 pm by wraper »
 
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Offline Yansi

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Re: How often do you see fake chips?
« Reply #31 on: October 05, 2019, 01:55:47 pm »
seen lots of fake 2n3055 tranys from ebay that short at 1 amp.

Well, 2n3055 tranny even in original state and form is so much shit these days it will not work in many applications.

Avoid using 2n3055 at all costs. There are way better cheap and reliable power NPNs these days.
« Last Edit: October 05, 2019, 01:58:23 pm by Yansi »
 

Offline GerardG

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Re: How often do you see fake chips?
« Reply #32 on: October 09, 2019, 08:02:20 am »
Got some fake lately.

Got some RGB leds that had anode at the opposite side.

Got some battery charging chips. I designed on microchip part that can have a 67k resistor on the Prog pin. The used part only works with maximum 20k on the prog pin.

This 20k was also mentioned in a datasheet for a pin compatible Chinese chip.
Assembly company showed the packing list for the components they bought.


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