Watch out for fake 74LS logic ICs.

[tooki]

No problem! I didn’t check, but chances are that Mouser and Farnell are the same.

[girishji]

As someone who lived in US for decades I can say it is cumbersome and expensive to get parts in Poland. In addition to expensive shipping there is VAT (daylight robbery). Some of the things I want are only on Mouser EU (ships from Chech) and some parts are only available to US customers. Digikey and Mouser are about the same. Farnell has less selection but cheaper shipping (VAT is inescapable). If you want something interesting it will most likely be missing on farnell. TME is still cheaper but even limited selection. Finally allegro for common cheap stuff. Difference in cost b/w US and EU becomes obvious when you order pcb's from jlcpcb.

[magic]

LOL, what are you doing in this shithole?

Finally allegro for common cheap stuff.

Doable, but you really need to know what you are doing or you end up brainf*cked like the OP.

(For those not in the know, it's our local scambay/scamazon kind of site).

[tooki]

As someone who lived in US for decades I can say it is cumbersome and expensive to get parts in Poland. In addition to expensive shipping there is VAT (daylight robbery).

How long has it been since you actually ordered from Digikey, Mouser, or Farnell to Poland?!?

I didn't check Farnell, but Digikey and Mouser both ship DDP incoterms, which means VAT is covered by the seller. DDP means it arrives to you with all customs clearance done.

This wasn't always the case, but has been for a few years now.

Some of the things I want are only on Mouser EU (ships from Chech)

Nope. While they have a sales office there, Mouser has exactly one warehouse for the entire world, and it's in Texas.

Similarly, Digikey has exactly one warehouse for the entire world, and it's in Minnesota.

Farnell has less selection but cheaper shipping (VAT is inescapable).

No, if it's DDP incoterms, VAT is already included.



FYI, while Digikey shows the incoterms right on the screen where you select the country and currency, Mouser's website currently sorta hides it (probably by mistake; it used to be easier to find). But here's how to check without having to put stuff into the cart:
Visit https://www.mouser.pl/mvc/header/CurrencySelection but replace ".pl" with the TLD for your country.

Now, in some cases (like Poland) it varies depending on shipping method, or even gives you the choice of incoterms. This is accessed by clicking the "More delivery options" link in the cart. The first screenshot shows what it looks like for an example €96 order (i.e. eligible for free shipping, since >€50) on mouser.pl.

As you can clearly see, the default option, the free shipping, is DDP incoterms where you owe nothing more because it's already been collected.

The current incoterms are also shown in the cart itself, see second screenshot.

[Co6aka]

I never really considered ebay a dependable source for components

Wow, I must have missed all the changes... Used to be that eBay didn't sell components or any other goods because eBay was a platform for independent merchants to offer their wares on.  Certain independent merchants were offering the fake stuff so many people preferred to buy because it was lower-priced than the genuine stuff other independent merchants were offering...but very few people were buying because it was higher-priced than the fake stuff.  Gresham's Law prevailed and the independent merchants offering the higher-priced but genuine merchandise scrapped it and/or closed down their listings.  Buyers prefer the lower-priced fake merchandise, and Brawndo's got what plants crave!

[Fflint]

LOL, what are you doing in this shithole?

Finally allegro for common cheap stuff.

Doable, but you really need to know what you are doing or you end up brainf*cked like the OP.

(For those not in the know, it's our local scambay/scamazon kind of site).

Shithole? Were you perhaps educated by the Soviet installed education system during the bygone era or shortly after? Many people at the time were thought to hate their own country at the time. Believe me, it can be cured. Best way is to live elsewhere for a while (not, just going for the summer, but actually living your life there for good number of years, buy a car and a house, change few jobs, use healthcare and gov services etc) then come back and tell me "it's a shithole" again.

As for the site, I use it (and olx) all the time(as buyer and seller) and I never "got scammed" or "brain***ed". The seller did return my money and he even contacted me few days later offering me chips from another manufacturer for free. I declined, because I already got my chips elsewhere. In all likely hood he was scammed by his supplier.

As someone who lived in US for decades I can say it is cumbersome and expensive to get parts in Poland. In addition to expensive shipping there is VAT (daylight robbery).

How long has it been since you actually ordered from Digikey, Mouser, or Farnell to Poland?!?

I didn't check Farnell, but Digikey and Mouser both ship DDP incoterms, which means VAT is covered by the seller. DDP means it arrives to you with all customs clearance done.

This wasn't always the case, but has been for a few years now.

I never lived in US so I can't compare, but I did live in the UK for over 15 years. I wouldn't say getting parts in UK or Poland is any more or less cumbersome. Of course back then UK was in the EU(so shipping from and to EU was easy) and I lived a driving distance from the Farnell's sales counter in Leeds so that was nice, but their prices meant I usually shopped elsewhere anyway. Mostly on Ebay and via various small stores same as I do in PL now.

As for VAT, I hate it too, but the problem is not who pays it, but that it is there. In UK it was 19% in PL it is 23% (ouch). However it is important to note in US prices are given excluding local sales taxes. Depending on the state it may mean nothing on top, or 12% on top. It is way lower than 23% of the VAT. I don't like it, but there is some consolation we do get more rights as buyers. For example any internet purchase in EU can be returned for no reason within 14 days, and warranty is compulsory for 2 years for individuals. I believe many stores offer the same or better in US, but not all.

Some of the things I want are only on Mouser EU (ships from Chech)

Nope. While they have a sales office there, Mouser has exactly one warehouse for the entire world, and it's in Texas.

Similarly, Digikey has exactly one warehouse for the entire world, and it's in Minnesota.

Are you sure of that? Last time I bought from Mouser EU they charged me about 60pln for shipping (about $13) and the order came in under a week.  That's very cheap and quick shipping if they indeed ship from Texas.  This seems to suggest they have an outfit in EU (maybe a shipping depot)?

I can't say for digikey.

Farnell has less selection but cheaper shipping (VAT is inescapable).

No, if it's DDP incoterms, VAT is already included.

As for Farnell last time I ordered (2 years ago) I got an impression it came from another EU country too. I can't be sure though.

Coming back to the subject of this post I recently bought a batch of Ti's 74LS133 from an Aliexpress seller for few $. They were significantly cheaper than all other options, but not stupid cheap (0.99$ free shipping - that woukd be just suspicious). They came in yesterday and as far as my testing can say they are legit...

Here's a photo:


This shows not all Aliexpress sellers are dodgy and applying some common sense (not going for cheapest, looking at reviews) can mean a good experience.

[wraper]

Imho sanded, blacktopped, relabeled. Try rubbing marking with acetone or some other solvent.

[wraper]

The have e4 marking which does not match with solder dipped terminals as it looks from the photo.

e0 - contains intentionally added lead (Pb)
e1 - SnAgCu (shall not be included in category e2)
e2 - Sn alloys with no Bi or Zn excluding SnAgCu
e3 - Sn
e4 - Preplated (e.g., Ag, Au, NiPd, NiPdAu)
e5 - SnZn, SnZnx (no Bi)
e6 - contains Bi
e7 - low temperature solder (≤ 150C) containing Indium (no Bi)
e8, e9 - unassigned

[ale500]

I got some 74HCT245 from aliexpress... they draw like 50 mA with all inputs at fixed values...

[magic]

Shithole?

It was depressing to discover that we were the better side of the Iron Curtain after all, but those losers don't need to know about it.
My comment wasn't directed to you, pls no bully

As for the site, I use it (and olx) all the time(as buyer and seller) and I never "got scammed" or "brain***ed". The seller did return my money and he even contacted me few days later offering me chips from another manufacturer for free. I declined, because I already got my chips elsewhere. In all likely hood he was scammed by his supplier.

Yeah, you didn't get scammed, you just wasted your time and had to buy elsewhere.
And if the part worked 99% right except for that 1% you spent a whole day debugging, then you'd see what brain***ed means.
Pro tip: learn to tell apart old electronics shops selling their 1990s stock from Chinesium importers.

Coming back to the subject of this post I recently bought a batch of Ti's 74LS133 from an Aliexpress seller for few $. They were significantly cheaper than all other options, but not stupid cheap (0.99$ free shipping - that woukd be just suspicious). They came in yesterday and as far as my testing can say they are legit...

I would say they look fake, but can't be 100% sure because there have been several variants of TI logo over decades, maybe I haven't seen them all yet.
They look laser etched so the markings won't come off with aceton, obviously. But wrong package option marking would be a serious indicator something is wrong.
Check if the pins are fresh and stiff and have no traces of cleaning and re-tinning.

FYI, every single chip on this photo was fake. The only way to be sure is take them apart. Just because it looks similar to the original and passes simple tests doesn't mean it's the real thing and will meet all specs.

Common types of fakes are recycled chips, similar but cheaper chips, similar recycled chips, or modern Chinese equivalents with fake markings applied right at the factory.

[wraper]

They look laser etched so the markings won't come off with aceton, obviously.

It does not work on laser etching as such but often works on paint by which relabeled chips get coated on top. Though if chips get heated to high temperature then you no longer can remove the paint IME. Like you can easily remove paint before reflowing the board but not afterwards.

[amyk]

So here we have it. I suspect those are not even TI chips (on account of the propagation delay being so much higher), but some other make. Perhaps they are rejects from manufacturing that failed self oscillation/crosstalk tests. Do logic manufacturers do such tests? I have no idea.

The delay looks more like an old CMOS logic family, and so does the "rail to rail" behaviour of the output that you saw with the sine wave.

[Fflint]

Imho sanded, blacktopped, relabeled. Try rubbing marking with acetone or some other solvent.

 

OK, I have to take back what I said before... Not buying the cheapest and looking at ratings doesn't protect you from buying fake :-/

Now, this is interesting to me. I'll definitely be decapping some of them to see the die.

Shithole?

It was depressing to discover that we were the better side of the Iron Curtain after all, but those losers don't need to know about it.
My comment wasn't directed to you, pls no bully

OK, np.

As for the site, I use it (and olx) all the time(as buyer and seller) and I never "got scammed" or "brain***ed". The seller did return my money and he even contacted me few days later offering me chips from another manufacturer for free. I declined, because I already got my chips elsewhere. In all likely hood he was scammed by his supplier.

Yeah, you didn't get scammed, you just wasted your time and had to buy elsewhere.
And if the part worked 99% right except for that 1% you spent a whole day debugging, then you'd see what brain***ed means.
Pro tip: learn to tell apart old electronics shops selling their 1990s stock from Chinesium importers.

I didn't spent a whole day debugging. There is a lot of text in this thread so details like this get lost. I had my doubts from the moment I saw them. The moment I plugged one into the device (a c64 cartridge) and it crashed every time it used I swapped the chip for known good one. The debugging took less than 5 min. However, as mentioned it is interesting to me that those chips passed the logic test so then I spent a day probing them further out of curiosity.

Quite likely I'll spend even more time on the new chips I got that turned out to be fake... As I plan to decap them to find out what are they really. Do I have to do it? No, not really. Then there is an issue of leaving feedback on Aliexpress. I told the seller what I think about those chips and it is likely he'll refund me. I wonder if I'll be able to leave feedback then to warn others, or will the refund essentially cancel the transaction. We'll see.

Coming back to the subject of this post I recently bought a batch of Ti's 74LS133 from an Aliexpress seller for few $. They were significantly cheaper than all other options, but not stupid cheap (0.99$ free shipping - that woukd be just suspicious). They came in yesterday and as far as my testing can say they are legit...

I would say they look fake, but can't be 100% sure because there have been several variants of TI logo over decades, maybe I haven't seen them all yet.
They look laser etched so the markings won't come off with aceton, obviously. But wrong package option marking would be a serious indicator something is wrong.
Check if the pins are fresh and stiff and have no traces of cleaning and re-tinning.

FYI, every single chip on this photo was fake. The only way to be sure is take them apart. Just because it looks similar to the original and passes simple tests doesn't mean it's the real thing and will meet all specs.

Common types of fakes are recycled chips, similar but cheaper chips, similar recycled chips, or modern Chinese equivalents with fake markings applied right at the factory.

Yes, they are fake, and the marking does come off with acetone... Pity.  Other than decapping I'm interested in checking if they match the parameters of the real chips. Do they suffer similar self resonance issues etc. O

[magic]

LOL, that's a lousy job. On better ones I could barely get rid of the black paint with nitric acid.

This means they are probably recycled chips. You can often tell by the pins being weak and fragile and sometimes tinned unevenly. It helps to have some genuine brand new chip for comparison.

They may be the exact type you ordered  and most of them still functional, or something similar. Somebody suggested an equivalent CMOS gate, that wouldn't be out of question.

Enjoy your Chinese roulette, you have been warned

[wraper]

You can often tell by the pins being weak and fragile and sometimes tinned unevenly.

Leads are fragile when old leads were cut off and new leads welded on. But AFAIK it's more common with power transistors, power ICs and parts in metal can.

[magic]

Those DIP leads have been factory bent, then bent some more for insertion, then abused during desoldering and cleaning, then bent back to factory angle, then shoved into foam by the retailer. They tend to become softer due to metal fatigue, sometimes to the point of breaking on the slightest excuse.

[wraper]

Those DIP leads have been factory bent, then bent some more for insertion, then abused during desoldering and cleaning, then bent back to factory angle, then shoved into foam by the retailer. They tend to become softer due to metal fatigue, sometimes to the point of breaking on the slightest excuse.

If it's the case, leads will be noticeably ugly. If they look new but easily break, they are welded on.

[Fflint]

If these are the actual chips, but desoldered, that woukd be fine by me, but I verh much doubt that. If they were original chips, why grind off markings?

My logic tester tells me all chips have the right logic function, so they're either rebadged 74HC (much cheaper) - I'll test that by sweeping the inputs, voltage threshold is different in LS and HC, or maybe they don't meed requirements elsewhere(noise, frequency etc).

I wonder when counterfeiting such cheap chips what method could be used to do it efficiently and still be profitable when selling them so cheap. People say they are pulled out of "trash" (as in old electronic devices). Just think how much labour it will take to remove them, sort them out(remember they do pass simple logic test) , grind them off, relabeled, sell them for pennies and still make profit? I can only guess, but I think it would be much more profitable to get some kind of Chinese made simple programmable logic, have them preground and blackened, when an order comes in, program the function, print the marking and away it goes.

That's why I'm interested in how they do it and why I want to decap it. I'm kind of 50/50 expecting genuine ti reject, a different brand HC or some programmable logic. As far as I know no one decapped those fake 74ls Ali chips.

Also, for people who want to roll the Chinese roulette wheel too, I would say the feedback process on Aliexpress is scammy as f***. For example I can't leave feedback if I opened a dispute. No option regardless of outcome. So if one has bad experience, one has to click "received item" which sends the money to the seller, then leave negative feedback, then open dispute. How many people are going to do that?

I think I must have been very lucky to get so much good stuff from China through the years and only encountered this kind of fakery now. Maybe because I almost always bought used stuff? I very rarely buy stuff marked new.

[amyk]

With that propagation delay, it's not HC. Might be a CD die that's been rebonded, or 74C.

[wraper]

If these are the actual chips, but desoldered, that woukd be fine by me, but I verh much doubt that. If they were original chips, why grind off markings?

To make them look brand new.

My logic tester tells me all chips have the right logic function, so they're either rebadged 74HC (much cheaper) - I'll test that by sweeping the inputs, voltage threshold is different in LS and HC, or maybe they don't meed requirements elsewhere(noise, frequency etc).

Measure current consumption, it's the most obvious difference between TTL and CMOS.

[magic]

AFAIK no bipolar logic can swing all the way up to VCC on the output, so I think that could be an easy test.

I wonder when counterfeiting such cheap chips what method could be used to do it efficiently and still be profitable when selling them so cheap. People say they are pulled out of "trash" (as in old electronic devices). Just think how much labour it will take to remove them, sort them out(remember they do pass simple logic test) , grind them off, relabeled, sell them for pennies and still make profit? I can only guess, but I think it would be much more profitable to get some kind of Chinese made simple programmable logic, have them preground and blackened, when an order comes in, program the function, print the marking and away it goes.

That's why I'm interested in how they do it and why I want to decap it. I'm kind of 50/50 expecting genuine ti reject, a different brand HC or some programmable logic. As far as I know no one decapped those fake 74ls Ali chips.

Yes, I think fake 74 logic is uncharted territory so far.

I expect same outcome as with 555 timers, opamps or voltage references: the more expensive stuff is recycled scrap, the cheapest offerings are Chinese substitutes with false markings, for reasons you already suspect.

Simple labor is cheap in China and they aren't using high technology for this. I recall a video about chip recycling posted somewhere on this forum. They were putting whole boards in a bowl of tin hanged over fire and pulling chips out with pliers, or something like that. Then the chips are sorted by type and either sold with original markings or "refreshed".

Also, for people who want to roll the Chinese roulette wheel too, I would say the feedback process on Aliexpress is scammy as f***. For example I can't leave feedback if I opened a dispute. No option regardless of outcome. So if one has bad experience, one has to click "received item" which sends the money to the seller, then leave negative feedback, then open dispute. How many people are going to do that?

Maybe they fucked it up recently, but I have a habit of leaving negative feedback only after I'm done recovering my money and I don't recall having problems with that on AE. And BTW, all feedback is deleted after 6 months anyway. The Chinese know best that consistency is not a thing that exists in China

Money is not sent to the seller until two weeks after delivery confirmation. That's why you have two weeks to open dispute and AE guarantees your money back if they take your side.

[tooki]

Some of the things I want are only on Mouser EU (ships from Chech)

Nope. While they have a sales office there, Mouser has exactly one warehouse for the entire world, and it's in Texas.

Similarly, Digikey has exactly one warehouse for the entire world, and it's in Minnesota.

Are you sure of that? Last time I bought from Mouser EU they charged me about 60pln for shipping (about $13) and the order came in under a week.  That's very cheap and quick shipping if they indeed ship from Texas.  This seems to suggest they have an outfit in EU (maybe a shipping depot)?

They use these nifty things called “airplanes” to quickly get things from one place to another.

And because they do that tens of thousands of times each day, they get massive discounts with the shipping companies.

So yes, I’m quite sure. We use Mouser and Digi-Key all the time at work (like, usually several orders a week), and those packages always come from USA. It says so on the boxes, but you can also easily check by using the tracking number of your shipment.

Honestly, it is impressive that they can get things sent so quickly, but that’s because they a) get your package out the door extremely quickly, and b) do a lot of pre-sorting themselves. Mouser and Digi-Key in essence have the first step of a UPS/FedEx depot within their facilities. So the shipping company isn’t picking up thousands of random packages, but rather bins that are already sorted by what airport they are headed to next. For example, Zurich is served by the UPS depot at the Cologne airport, which is a direct flight from the main UPS depot in Kentucky, USA. So Digi-Key will put any package to me in a bin to Cologne, and when UPS comes, they take that bin and know that everything in it goes directly onto the next plane to Cologne. And that’s how I can order it on Monday evening and have it Wednesday by lunch!

[Fflint]

Now then. I mentioned I'll do decapping and I did. I have a nice optical microscope, but I have limited photo taking capability (basically I hold the mobile phone to the microscope).

So here are the pictures of the die that is supposed to be SN74LS133N 82E24DKE4, also on the bottom of the chip plastic E9 is molded. It is supposed to be a 13 input Nand gate. It sure looks like one to me, but I have no idea about a brand. Do TI dies have a logo usually?




Does anyone recognise it? Especially that B 2133 marking? Is there some site with 74LS die photos(or any 74 series) ? I couldn't find one.

Also, for people who want to roll the Chinese roulette wheel too, I would say the feedback process on Aliexpress is scammy as f***. For example I can't leave feedback if I opened a dispute. No option regardless of outcome. So if one has bad experience, one has to click "received item" which sends the money to the seller, then leave negative feedback, then open dispute. How many people are going to do that?

Maybe they fucked it up recently, but I have a habit of leaving negative feedback only after I'm done recovering my money and I don't recall having problems with that on AE. And BTW, all feedback is deleted after 6 months anyway. The Chinese know best that consistency is not a thing that exists in China

Money is not sent to the seller until two weeks after delivery confirmation. That's why you have two weeks to open dispute and AE guarantees your money back if they take your side.

Well, that is surprising. Yesterday there was no option to leave feedback, today it appeared (a day after Aliexpress accepted my dispute). So I'll make sure to do it.

Unfortunately, I also noticed I must have made a mistake and disregard my own rule... The guy has only one review on this item. I usually don't buy from sellers that have less than 7~8 recent ones. This was a low value item and I bought it before my previous "fake chip experience" so yeah, my mistake for falling for it.

They use these nifty things called “airplanes” to quickly get things from one place to another.

And because they do that tens of thousands of times each day, they get massive discounts with the shipping companies.

So yes, I’m quite sure. We use Mouser and Digi-Key all the time at work (like, usually several orders a week), and those packages always come from USA. It says so on the boxes, but you can also easily check by using the tracking number of your shipment.

Honestly, it is impressive that they can get things sent so quickly, but that’s because they a) get your package out the door extremely quickly, and b) do a lot of pre-sorting themselves. Mouser and Digi-Key in essence have the first step of a UPS/FedEx depot within their facilities. So the shipping company isn’t picking up thousands of random packages, but rather bins that are already sorted by what airport they are headed to next. For example, Zurich is served by the UPS depot at the Cologne airport, which is a direct flight from the main UPS depot in Kentucky, USA. So Digi-Key will put any package to me in a bin to Cologne, and when UPS comes, they take that bin and know that everything in it goes directly onto the next plane to Cologne. And that’s how I can order it on Monday evening and have it Wednesday by lunch!

OK, fair enough. I too think it is impressive.

[wasedadoc]

Does anyone recognise it? Especially that B 2133 marking? Is there some site with 74LS die photos(or any 74 series) ? I couldn't find one.

Looks like S133 with B underneath to me.

[magic]

One of your images is mirrored
Assuming this is a 133 type chip, pinout suggests that the first (darkfield) image is correct. So the marking reads:

Code: [Select]

S133
 Bwhich makes sense, I guess. Perhaps the S even stands for Schottky.

The circuit is definitely bipolar and looks like a likely TTL NAND gate.

Most TI dice have a logo: letters TI in rectangle. See here.
Not sure who made this. Are base areas of transistors visible under brightfield? I can't really see them, but it could be just the quality of your image. If they are invisible, that strongly hints towards modern Chinese production. Which is perhaps good news in a way, it means somebody is still making these things.

Is there some site with 74LS die photos(or any 74 series) ? I couldn't find one. 

Well, there is https://project5474.org but not a lot in there.