i won't buy chinise parts from aliexpress or ebay

[wraper]

Why somebody needs to buy parts really cheap? Probably because there is a lack of income. Maybe the reason for the lack of income is using unqualified parts in the past and spending to much time on fixes.

Probably because someone is a cheapskate. I doubt that many of US or western EU residents are so poor and need so many parts that they need to buy 20 NE555 for $1.5.

I mean there are people who started this as a student (when their work could not yet generate income) and missed to change their habits later.

This should be closer to reality. However many people simply like to buy cheap as possible even if they always had the money.

[brabus]

This is a shock for me. I genuinely thought the buyers of Aliexpress/eBay were 100.0% hobbysts.

If a professional buys parts (single components, not semi-finished products) from Aliexpress/eBay for job related development activities, well... we have a whole lot to discuss here about the definition of "professional". I mean, the cost of the risk alone, computed by the time you wait for the shipment, makes zero economical sense.
The real cost of the items is way higher than the price tag.

I bought tons of stuff from eBay/AliExpress, got my good parts and bad parts, good shipments and bad shipments, but always got the value I paid for.
On the other hand I had major issues with Mouser/Digikey as well, but the cost of those issues had already been taken into account in the project. The extra price you pay is compensated by the quick shipping and the prompt support you get from them: unthinkable with eBay/Ali.

[BravoV]

I doubt that many of US or western EU residents are so poor and need so many parts that they need to buy 20 NE555 for $1.5.

Hmmm ... 555 chip, coincidentally, my experience even though not $1.5, maybe it was about $10 for a bunch about 30-50 pcs of CMOS version of 555 (TLC555), don't remember well as it was many-many years ago purchased from AE shop.

At that time, I was really prepared to receive fake 555 (non cmos version) as they're so cheap, but ended up all being genuine as I rigged up simple oscillator test circuit on breadboard below, and all run and still oscillated at 1.5v VDD, clearly not bipolar version, maybe luck was on me. 

[wraper]

I doubt that many of US or western EU residents are so poor and need so many parts that they need to buy 20 NE555 for $1.5.

Hmmm ... 555 chip, coincidentally, my experience even though not $1.5, maybe it was about $10 for a bunch about 30-50 pcs of CMOS version of 555 (TLC555), don't remember well as it was many-many years ago purchased from AE shop.

At that time, I was really prepared to receive fake 555 (non cmos version) as they're so cheap, but ended up all being genuine as I rigged up simple oscillator test circuit on breadboard below, and all run and still oscillated at 1.5v VDD, clearly not bipolar version, maybe luck was on me. 

There are many flavors of counterfeit 555. Them working without detailed testing/inspection proves nothing about them being genuine.

[SilverSolder]

My philosophy is:  if a part works well enough for my purposes, it is genuine enough! 

[bd139]

Same.

Talking of which just ordered some hooky MAV-11 MMICs 

[wraper]

My philosophy is:  if a part works well enough for my purposes, it is genuine enough! 

Until it bites you in ass and causes monetary loses exceeding component price 1000+ fold.

[dietert1]

Building a test setup for checking 555s is a total loss for a professional EE. Even worse if you need to check every single part.

I remember buying a minimal ADS1256 board from amazon to do some test. This was about € 40. It took me more than an hour to remove problems i found by visual inspection, lucky enough before applying power. Discarding faulty boards at amazon. Wrote a negative report at amazon. The offer disappeared, yet now the identical board is offered by somebody else for € 121. Won't buy, though.

Regards, Dieter

PS: The € 120 offer is for three pieces, so they can't setup a new offer for each unit sold but for each three sold units.

[SilverSolder]

My philosophy is:  if a part works well enough for my purposes, it is genuine enough! 

Until it bites you in ass and causes monetary loses exceeding component price 1000+ fold.

In which case - it would not work well enough for my purposes! 

There is a difference between taking calculated risks and being reckless.

[wraper]

My philosophy is:  if a part works well enough for my purposes, it is genuine enough! 

Until it bites you in ass and causes monetary loses exceeding component price 1000+ fold.

In which case - it would not work well enough for my purposes! 

There is a difference between taking calculated risks and being reckless.

Saying if it works for you = genuine enough is already reckless to begin with. Nowhere near to calculated risks.

[SilverSolder]

My philosophy is:  if a part works well enough for my purposes, it is genuine enough! 

Until it bites you in ass and causes monetary loses exceeding component price 1000+ fold.

In which case - it would not work well enough for my purposes! 

There is a difference between taking calculated risks and being reckless.

Saying if it works for you = genuine enough is already reckless to begin with. Nowhere near to calculated risks.

I'm curious why you would think that is reckless, without knowing what I think "works for me" actually means.

Let's take an extreme example:  what if I am using a transformer as a door stop in my office, just because I think it looks cool.  Would you consider it reckless to use a reconditioned, reclaimed transformer of unknown origin for that purpose?

[wraper]

Let's take an extreme example:  what if I am using a transformer as a door stop in my office, just because I think it looks cool.  Would you consider it reckless to use a reconditioned, reclaimed transformer of unknown origin for that purpose?

Reckless is when you use 5 tonne crane to hold 10 tonne weight. It might work for a while before some tragic accident happens. Which often happens with counterfeit transistors, diodes, voltage regulators, capacitors. When internals are significantly weaker in some aspect (voltage, current...) than marking suggests. Not to say that cheaper genuine parts from Chinese brands provide way more predictable results than more expensive parts with unknown internals.

[Bassman59]

Why somebody needs to buy parts really cheap? Probably because there is a lack of income. Maybe the reason for the lack of income is using unqualified parts in the past and spending to much time on fixes.

There is an observation here: "It's very expensive to be poor." This manifests in many ways, some of which might be non-obvious.

For example, if you're poor, you might not be able to go see the doctor for something easily treated. Or, even if you do, because you're poor (and in the US the poor generally don't have health insurance), the doctor might write a prescription that won't get filled because the medicine costs $100 and you have to choose between meals or the medicine. And as a result, without treatment, the condition becomes grave, and you end up in the emergency room. Now the $100 medicine and the $100 doctor's office visit look cheap compared to a $50,000 hospital bill.

Another example. You're poor, and you have a low-paying job (but you have a job) and you need a car to get to work. But you can afford only a junker car, which is unreliable, as opposed to a new car. And some days the junk car won't start so you miss a day of work. And if you miss enough days, you're fired.

I could continue but you see the point.

Now in this situation of being the poor college student who can only afford parts from Ali Express instead of DigiKey or Mouser, it's the same thing. You buy the Ali parts and hope that you chose a good vendor who won't fuck you and maybe you'll be able to build your project without spending endless hours trying to figure out why it fails. Or you could spend more and buy the parts from DK/Mouser and know they'll work and you can spend your time debugging your design rather than finding bad parts.

[SilverSolder]

Let's take an extreme example:  what if I am using a transformer as a door stop in my office, just because I think it looks cool.  Would you consider it reckless to use a reconditioned, reclaimed transformer of unknown origin for that purpose?

Reckless is when you use 5 tonne crane to hold 10 tonne weight. It might work for a while before some tragic accident happens. Which often happens with counterfeit transistors, diodes, voltage regulators, capacitors. When internals are significantly weaker in some aspect (voltage, current...) than marking suggests. Not to say that cheaper genuine parts from Chinese brands provide way more predictable results than more expensive parts with unknown internals.

Agree 100%.   But using a cheap transistor in a non-critical hobby circuit in your basement...  hardly reckless, and possibly a learning opportunity?

[Quarlo Klobrigney]

Unless the experimental device it's in, fails in such a way that tears a hole in the fabric of space-time.

[chickenHeadKnob]

Agree 100%.   But using a cheap transistor in a non-critical hobby circuit in your basement...  hardly reckless, and possibly a learning opportunity?

Wraper is correct even for the case of the young student tinkering in his basement. Not because of safety or any professional type risk but rather it is highly demotivational to have your project fail for mysterious reasons when you are just starting out. They will think did I goof up? is my circuit bad ?, etcetera . Leading some students to give up early in frustration. Experienced people have far better awareness and debugging skills so they detect the bad part quickly and move on,

In my teenage years I wanted to learn all I could about computers, both the programming side and hardware. This was during the 1970's so no internets, no online datasheets,  no digikey/mouser/ebay, and no arduino. My options consisted of going to the engineering library of one university 80kms away round trip to get photocopies out of the few data books they had and  buying parts from radio shack from the limited selection they had. There was also one hobby electronics magazine Electronics Today International edition that I followed, and I went to a second university 40 kms  away to steal mainframe time

No one I knew had my perseverance or auto-didactic drive to learn electronics and computing so by the time I reached the University level it was easy for me to obtain teaching assistant jobs in digital electronic lab classes. These  consisted of helping the 'tards students make basic circuits from 74 series parts and some pre-built modules. They would be stymied by the simplest of problems. Bent pin under chip because of ham-fisted insertion into breadboard, crap wiring, reversed power or no power connected. They also couldn't discern when the problem was simple connection error or if the chip was bad because the previous retard had destroyed it. Things which would hardly have slowed me down when I was a teen by myself would cause them to give up right away.

The situation with analog components is even worse as a bad but functioning part can depart from the expected datasheet in very subtle ways.

[SilverSolder]

Agree 100%.   But using a cheap transistor in a non-critical hobby circuit in your basement...  hardly reckless, and possibly a learning opportunity?

Wraper is correct even for the case of the young student tinkering in his basement. Not because of safety or any professional type risk but rather it is highly demotivational to have your project fail for mysterious reasons when you are just starting out. They will think did I goof up? is my circuit bad ?, etcetera . Leading some students to give up early in frustration. Experienced people have far better awareness and debugging skills so they detect the bad part quickly and move on,

In my teenage years I wanted to learn all I could about computers, both the programming side and hardware. This was during the 1970's so no internets, no online datasheets,  no digikey/mouser/ebay, and no arduino. My options consisted of going to the engineering library of one university 80kms away round trip to get photocopies out of the few data books they had and  buying parts from radio shack from the limited selection they had. There was also one hobby electronics magazine Electronics Today International edition that I followed, and I went to a second university 40 kms  away to steal mainframe time

No one I knew had my perseverance or auto-didactic drive to learn electronics and computing so by the time I reached the University level it was easy for me to obtain teaching assistant jobs in digital electronic lab classes. These  consisted of helping the 'tards students make basic circuits from 74 series parts and some pre-built modules. They would be stymied by the simplest of problems. Bent pin under chip because of ham-fisted insertion into breadboard, crap wiring, reversed power or no power connected. They also couldn't discern when the problem was simple connection error or if the chip was bad because the previous retard had destroyed it. Things which would hardly have slowed me down when I was a teen by myself would cause them to give up right away.

The situation with analog components is even worse as a bad but functioning part can depart from the expected datasheet in very subtle ways.

OK, that's a fair point.  I would also add that most of the time, components are cheap enough that we can buy new, high quality stuff and should not be tempted into the dark side.   

But that still leaves the situation where an experienced person buys cheap parts that he/she is familiar with, in the full knowledge that these are not prime parts...   in return for paying a lot less for them.

It is similar to buying a used car, or a "cheap brand" car, in my view.  If you are buying an old junker that has been repaired by dozens of people, with banana skins in the gearbox and differential to keep them quiet, you do not have the same expectations that you do when buying a brand new car -  and you don't expect to pay new car prices, in return for that.   You can also choose a cheaper brand of car.  You might have different expectations from a BMW compared to a Perouda, for example.  Does that make the Perouda buyer, or the used car buyer, a reckless person?  It all depends what their expectations or requirements are!

Why wouldn't the same principle apply with electronic components? 

[wraper]

OK, that's a fair point.  I would also add that most of the time, components are cheap enough that we can buy new, high quality stuff and should not be tempted into the dark side.   

But that still leaves the situation where an experienced person buys cheap parts that he/she is familiar with, in the full knowledge that these are not prime parts...   in return for paying a lot less for them.

It is similar to buying a used car, or a "cheap brand" car, in my view.  If you are buying an old junker that has been repaired by dozens of people, with banana skins in the gearbox and differential to keep them quiet, you do not have the same expectations that you do when buying a brand new car -  and you don't expect to pay new car prices, in return for that.   You can also choose a cheaper brand of car.  You might have different expectations from a BMW compared to a Perouda, for example.  Does that make the Perouda buyer, or the used car buyer, a reckless person?  It all depends what their expectations or requirements are!

Why wouldn't the same principle apply with electronic components?

Experienced person saves money by buying parts of lesser known Chinese brands. Buying on aliexpress/ebay is a valid option only for some sorts of parts, say you want to buy a Richetek PWM controller to repair a graphics card. Hard to obtain otherwise and chance of counterfeiting is very low. Otherwise it's like searching in a pit full of crap in hope of finding gold. You may find it, but in the process you will be covered in shit from top to bottom.

[SilverSolder]

OK, that's a fair point.  I would also add that most of the time, components are cheap enough that we can buy new, high quality stuff and should not be tempted into the dark side.   

But that still leaves the situation where an experienced person buys cheap parts that he/she is familiar with, in the full knowledge that these are not prime parts...   in return for paying a lot less for them.

It is similar to buying a used car, or a "cheap brand" car, in my view.  If you are buying an old junker that has been repaired by dozens of people, with banana skins in the gearbox and differential to keep them quiet, you do not have the same expectations that you do when buying a brand new car -  and you don't expect to pay new car prices, in return for that.   You can also choose a cheaper brand of car.  You might have different expectations from a BMW compared to a Perouda, for example.  Does that make the Perouda buyer, or the used car buyer, a reckless person?  It all depends what their expectations or requirements are!

Why wouldn't the same principle apply with electronic components?

Experienced person saves money by buying parts of lesser known Chinese brands. Buying on aliexpress/ebay is a valid option only for some sorts of parts, say you want to buy a Richetek PWM controller to repair a graphics card. Hard to obtain otherwise and chance of counterfeiting is very low. Otherwise it's like searching in a pit full of crap in hope of finding gold. You may find it, but in the process you will be covered in shit from top to bottom.

I guess another thing we are not mentioning is that you have to be experienced not just with electronics per se, but also with buying stuff via the various Internet shopping sites in general. 

After years of experience buying smelly stuff, you develop a "sixth sense" as a buyer and then the percentage of crap you end up with drops to quite acceptable levels.

[wraper]

I'd like to hear about in what kind of cases you get fake parts from Ali assuming you paid a reasonable amount of money and not dreaming of electronic parts growing on trees in China.

I received relabeled nvidia GPUs, one part number sold as another. Same silicon physically but config is not. Got one Toshiba stepper driver relabeled as another. Found out by measuring pins, if I didn't do so, I would have explosion and probably burnt traces in my device. Got relabeled UV EPROMs, 25V part relabeled as 12.5V. Got mix of attiny24 and 24A blacktopped and relabeled as 24A with a fresh date code, terminals soldered like shit. Those were not insanely cheap. For components which could be obtained from normal distributors it was the same or a little bit lower price than you would expect from Mouser or similar at qty of 100-1000.

[wraper]

Also once AD8293G160 was out of stock everywhere and I needed them urgently. Ordered few hundred from aliexpress at the price which was even higher than from distro. They were new and genuine but defect rate was like 20-25% with various issues, especially at one end of the tape where it was worse than 50%. I suspect it was some serious ESD. It was not popcorning due to moisture since they were bad even with hand soldering.

[asmi]

Amazing. That's all I can say. So it seems sellers do tend to sell fake parts knowing you can't return them economically

I once got incorrect chip (wrong P/N) on Aliexpress, and through dispute demanded refund without return because the latter is not economical, Aliexpress agreed with me and refunded the full amount.

[wraper]

I received relabeled nvidia GPUs, one part number sold as another. Same silicon physically but config is not. Got one Toshiba stepper driver relabeled as another. Found out by measuring pins, if I didn't do so, I would have explosion and probably burnt traces in my device. Got relabeled UV EPROMs, 25V part relabeled as 12.5V. Got mix of attiny24 and 24A blacktopped and relabeled as 24A with a fresh date code, terminals soldered like shit. Those were not insanely cheap. The same or a bit lower price than you would expect from Mouser or similar at qty of 100-1000.

Amazing. That's all I can say. So it seems sellers do tend to sell fake parts knowing you can't return them economically, which I never had to encounter. I mean I did buy from China when I was in the US, but I use the same Taobao and I never got duds, probably due to less language barrier and the seller knowing I have connections in China that can return the goods or even dispute him.

If you find out in time. Those attiny were made quite convincing. Unfortunately I did not compare of date/lot code on top and bottom as they should match (they did not). Found out only during testing after they were placed on 100-ish of boards. More than half of the boards consumed like 2mA more than normal, other consumed as they should. When I checked date code on the backside, it became clear that those which consumed more were made before 24A was even released.
Stepper drivers sat in my drawer a few years before I decided to actually use them.

[bd139]

Amazing. That's all I can say. So it seems sellers do tend to sell fake parts knowing you can't return them economically

I once got incorrect chip (wrong P/N) on Aliexpress, and through dispute demanded refund without return because the latter is not economical, Aliexpress agreed with me and refunded the full amount.

Yeah same here. I’ve had broken stuff and fake stuff and aliexpress always sides with the buyer if you get them involved.

[PlainName]

with banana skins in the gearbox and differential to keep them quiet

One learns something new every day!