my fake 4017 runs backwards ??? fake components - Page 1
Forum section: electronics / projects

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 26, 2015, 06:33:36 pm
content: I'm trying to find out if fake components that you buy are actually generally better or generally worse than the originals. They are certainly cheaper ! I find most of the rhetoric on the net is about spotting fakes and talks about things that do not matter to me or the final circuit, like aesthetics. None of them actually mention if the part works better or worse than the original. Like, when they started making resistors, you were stuck with large tolerances. But with advances in manufacturing, the tolerances are so tiny today that they can't even make big enough mistakes for 5 % or 10 % tolerances, they just make them all at less than 1 % tolerance and label them as 1, 2, 5, 10 or whatever percentage the customer wants. Everyone gets the good product because nothing else is made anymore. I want to know are parts manufacturers same as the music industry where it's all about the money rather than the artists.http://tinyurl.com/krr75tpAll I hear is 'China bad this' and 'China bad that' but all of my best buys come from china. The reality I see on my desk is so different to what I hear about China. "genuine" parts have product recalls. Any search brings up stories about genuine product failshttp://tinyurl.com/nw5h9kuand just because you use ALL new ALL genuine MILitary grade expensive parts doesn't seem to help. They initially spent more than double what it cost to go to the moon on the F-35, but it's craphttp://tinyurl.com/qfpzetzhttp://tinyurl.com/q9r72dtHas anyone other than the people who SELL genuine parts have problems with fakes, WHICH genuine parts don't have ?I've had plenty of failed expensive parts, bought from reputable places, and plenty of cheap parts that do the job. I can't actually tell if an IC is real or not, I can only guess based on what it cost, and I don't notice any differences. 4017's seem to all go forwards contrary to the titleBut has anyone found a consistently bad item that people can actually watch out for or is it all good with cheap parts. Does cheap mean fake ? I know expensive too often fails and boy do I remember those !!

author: dmills
author_rank: Super Contributor
timestamp: August 26, 2015, 08:13:33 pm
content: Oh god yea...I have had fake caps that didn't make ripple current rating (Expensive mistake that was, we only found out after 6 months when the returns started....).Fake transistors that in no way came close to the power handling of the originals (Caught that one).Then there were the fake TDA2030s kicking around a year or so back, worked fine, but the short circuit protection circuitry didn't....I eventually swore off grey market parts, just too chancy when the electronics BOM is usually only 30% of the product BOM (And maybe only 10% of the selling price), way I figure it, ONE product recall avoided pays for all the difference between grey market and Arrow/Avnet pricing.A biggie to watch is opamps, where due to the commonality of the pinouts there is a thriving market in re labelling cheap parts as their higher performing cousins. Now sometimes it does not matter, because you are using the better part because it reduces the number of inventory lines or such, but sometimes it REALLY matters.If you are building one for personal use and time does not matter to you then by all means use the grey market stuff, but if you are building hundreds, or if the time tracking down problems matters then the authorized distributors are the only way to fly.Regards, Dan.

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 26, 2015, 08:28:51 pm
content: Quote from: dmills on August 26, 2015, 08:13:33 pmCool, thanks for the decent logical response. The caps part is interesting. I expect that can be measured by beginners, however it is so easy for hobbyists to simply use additional ones, like in parallel, especially where they go through the parts box. I think more often than not I end up using larger caps than called for because that's what I've got.I do think of getting back into making electronics products, but it ALWAYS strikes me as compulsory that whatever the part, whatever the source, I'd test them before putting them in. I've worked in places where there has been good, bad, and APPALLING quality control and bosses that are just barking mad and stupid and won't do the most simple quality control.I would expect that if bad products are getting to market, it IS more about poor setup of quality control than bad components. It's like you said how YOU caught one lot. I think there is no reason why proper quality control should avoid testing components. I wonder if 'bad parts' and 'bad tools' are just excuses for'bad management'.I guess if I do return to manufacturing then I'd probably be putting more time into testing components, especially in-system than most. I'd be mortified to find a product I sell was poor quality. Cheap parts overspec fine, but poor quality no. Thank you for the thoughtful response Dan.

author: dmills
author_rank: Super Contributor
timestamp: August 26, 2015, 08:56:34 pm
content: The trouble is that for the most part you do not ever handle the parts once the prototypes are done.Very few companies stuff their own boards, it is just not cost effective unless you are Sony, what actually happens is that you prepare a set of PCB files and a BOM and farm that package around contract assembly houses looking for one to build a few hundred for you.Because of this you need to ensure that for any part where it remotely matters you specify a manufacturer and part number (1000uF 50V is not sufficient you need to specify Cornell Dubillier, AFKXXYYYZZZ.......), and any contract assembler that I catch subbing specified parts for knockoff units gets permanently added to my 'no way in hell' list.Even for generics (jellybean R's, C's, Ferrites and the like) my BOMs list a range of acceptable manufacturers and require approval to use anyone else.As I say, parts are such a small component of the system price that unless you are doing hundred thousand unit runs the savings are negligible and if you are doing 100K unit runs the risks make it not worth it.Regards, Dan.

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 26, 2015, 09:06:38 pm
content: Quote from: dmills on August 26, 2015, 08:56:34 pmI like the name of that list !QuoteYes, I'd be doing smaller runs and could easily pick up problems, parts being as cheap as they are, it's easier in my case to overspec anyway, so subs are like meh. It's a lot different than putting two capitalists in a room and watching what happens. The designer who wants to save money Vs the factory that wants to cut corners.

author: dmills
author_rank: Super Contributor
timestamp: August 26, 2015, 09:40:21 pm
content: Quote from: TheElectricChicken on August 26, 2015, 09:06:38 pmReally?Those caps worked perfectly when they were installed, and the things passed a week in the soak rack just fine, picking up a problem that only appears after 6 months or so is HARD (And doubling up would probably not have helped, we concluded that is was a poor quality seal at the bottom of the can).You will always get some failures, it is a fact of life, but an entire bad batch for CDW, Chemicon or Panasonic is almost unheard of (And actually the failures there are astonishingly rare), further if you do get a high failure rate the FAE will usually arrange for the failed parts to be analysed and you will be told (most likely) what you were doing wrong, or (seldom) what the issue was.Even for hobby projects, it is worth the extra to know that when it does not work it is because you designed it wrong rather then because that '4017' was not!Regards, Dan.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 27, 2015, 02:12:41 am
content: I will second the notion that you should use "known good parts" on things that matter. Things that matter include medical devices, military equipment, aerospace equipment, space gear, and anything where you have to stand behind the quality of what you are selling. While there are problems that occur with "known good parts" there are far fewer than with grey market parts, and there is at least a chance of economic recovery if you can show that your parts were not what they were claimed to be. Your links to problems with major programs don't shed much light on the issue. We don't know how much care Apple takes, we don't know if Apple was lied to, and the F-35 problems have nothing to do with components. There are component problems in aerospace programs. Occasionally they result from manufacturing errors from major vendors, but they are with ever growing frequency due to fraud and forgeries where somewhere along the line someone who knew the parts were substandard passed them off as something they were not.The following paragraphs summarize some of the things I have been exposed to.Grey market parts come from many sources. One common source is parts which failed some part of the manufacturers requirements. These failures could be purely cosmetic. They could be a paperwork failure, the genesis of materials and components used could not be verified. Parts like this are just fine, although you will never know for sure about the paperwork failures. The failures could be due to a failure of some minor test parameter which doesn't matter in most applications. Most parts are not tested over temperature, but manufacturers do usually do something to assure themselves that the parts will work over the specified temperature range. This could be testing lot samples, or correlating an ambient temperature measurement to performance over temperature or some other technique. Many grey market parts are those which failed this screen. Will they work over temperature? Yes in many cases, but some will not. Failures can be as simple as inadequate environmental control on parts. (Look up "popcorning". Such parts can be used, but require significant pre-treatment at real expense. The problem comes when you don't know you need to do it.)Grey market parts also come from fab houses which have designed some form of a clone of a part, anything from using a copy of the mask set to a complete new design. This introduces risk to a user in several ways. First, it is often unclear if their design meets the same specifications as the original part. Second, it is unfortunately too common for a products performance to depend on non-specified performance. The simplest example of this would be your resistor example. If someone's design depended on 1% performance in 5% resistors, because it is common, and then got parts from a shop that hadn't mastered precision manufacturing his component would fail. Similar things happen with semiconductors, but it isn't quite as obvious as the resistor case. A prototype that works because the power supply rejection of the op-amp is actually far better than specified, or the input offset is lower or such things. Such designs can fail when "known good parts" shift within their tolerances. They are even more likely to fail when buying parts whose similarity to those in the prototype is likely to be lower. Other risks from clone parts can be even more subtle. Many PGAs and other parts when supplied in a plastic package are not even closed in plastic. There is a vent hole filled with a grease like substance. The properties of this substance are carefully chosen to be compatible with materials inside the package and to provide the needed protection from the outside world. A grey market fab may not have access to this magic material, may not be aware of its need, or just want to cut cost and will use something from the local emporium. It will work fine, for a while.

author: TheElectricChicken
author_rank: Frequent Contributor
timestamp: August 27, 2015, 02:35:49 am
content: Pretty much all of that points not at 'genuine components' but better in-factory testing. There was a video of a Chinese factory put up before, making mobile phones, don't know the link for that thread, but in the factory they seemed quite involved in testing their products thoroughly before they left the factory. If you have a great component level testing regime at pre-production then it wouldn't matter what you fed that machine, only the toughest would survive. It would also catch all the 'genuine' mistakes (pun?)I'm not sure if I explained my resistor example properly. In earlier days when they were first being made, the resistors may have been less predictable in their final resistance, so testing and then labeling them before sorting them out would be the go. One old production line trying to make 100 ohm resistors might have made half within 5 ohms of target, but still sold them all after testing and correct labeling. With progressively more consistent production lines over time, the resistors made would have all fallen within 5 ohms of 100. Then still later within 3 ohms, later 1 ohm and now it may well be quite fractional. So the intention to produce a 100 ohm resistor today in the factory may well only produce 100 ohm resistors plus or minus .2 ohms. If that is the case, then how do you sell to people who want 5%, 2% 1% and 10%. You can't dust off old production lines, you just make them all on the one line and paint on 1, 2, 5, and 10% markings. That's all correct and above board because they are within spec. All customers are happy. So when it comes to a genuine 5% resistor, I can choose some USA 5% resistor, or a cheap Chinese knock-off which may well be made in the single factory which churns out 500 times as many resistors as the US counterpart. Will the quality suffer ? obviously not. There are threads full of people and web pages full of morons who are feigning obsession with original parts and I don't see them doing anything else except looking at aesthetic qualities and cases and so on. I do not see anyone doing large scale testing at all, (except in the Chinese factory video, but that's different) Here I'll give you the first pages I came to when I searched for fake ic's.http://www.aeri.com/counterfeit-electronic-component-detection/The entire page is filled with nothing but aesthetics and nothing indicating there is anything different at all in the electrical characteristics of the components. You'd think there would be at least a single example suggesting that there is some electrical difference, however it's obvious as day this is just like pirate music detection. The music is the same music and can't be detected as different to the ears, and you have to concentrate entirely on the packaging. The whole argument is about packaging and nothing else, and it's all about one company fighting another, or one country fighting another. It's comparable to racism really, where there is no logic of any kind except repetition. That page is badmouthing China, and of course, the website is a Californian company. Every other part of the world outside the sphere of US influence just looks INSIDE the part at the electrical characteristics, same as you evaluate any two regular products for quality before choosing on price if they are the same. Apparently the sole differences that the Californian firm can come up with is stuff like scanning with microscopy in an examination of the package. The only reason they give for the entire exercise is apparently 'you must buy american' and why ? 'because you must buy american' same as you ask a parrot which tells you it wants a cracker, why it wants a cracker, and it's going to respond that it wants a cracker. I don't see any large scale testing to suggest that for example genuine Chinese brands are anything other than cheaper than US counterparts. China has a manned space program, and space station program the US government doesn't, NASA has concluded all that and just buys tickets now. It's manufacturing as far as I can see is nothing special, and when I ask to see proof that it is, all I'm getting is repetition at most. Where is there a page of testing? ( not the bloody case, but the product itself inside the case )

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 27, 2015, 04:06:47 am
content: ElectricChicken, read what I said. Those are all real examples from my personal experience. As I said, cosmetics may be the only difference, and then the parts are fine. Use them. But there are other cases.I didn't pick on China (though others in this blog often do). China IS one of the largest sources of bad components, and also one of the largest sources of good ones. Comes from being one of the biggest players, if not the biggest player, and from a somewhat randomly regulated economy. I am sure that the Chinese space program takes steps to assure the quality of their components. Space programs are one of the few examples where the approach you suggest really works. Few can afford to do 100% testing over all corners of the performance specification. It makes sense in space applications because the enormous launch costs make the cost of failure immensely high. I worked for a military supplier. Even in that industry we didn't do 100% testing of everything. Design prototypes and/or initial production units were exhaustively tested. Most items got a fairly comprehensive (but not exhaustive) test at room ambient temperature. Some programs got limited testing of each unit under temperature and vibration environments. Most did lot sample testing of some sort or another (there is an alphabet soup of approaches to minimize test cost while maximizing screening effectiveness of the tests.) Even this scaled down testing is enormously expensive, and doesn't catch everything.I worried that my use of the resistor example would be mis-understood. I agree completely with you on the history of resistor manufacture. I chose that as an example because resistors are a very simple device. In many cases you can ignore odd parameters like shunt capacitance, inductance, voltage breakdown, temperature coefficient, etc. Any semi-conductor is much more complex. If a naïve designer picks a resistor value for his circuit that works, but is critical (that is, a change of a few percent will significantly change function), he may do fine when buying from any of these established vendors who have polished their processes over time. Maybe he even realizes that it is critical, but he "knows" that 5% resistors are really 1% because of industry maturation. But then his equally naïve purchasing department finds a good deal from a new vendor who offers 5% resistors for an attractive price. Maybe even below their cost so they can get a foot in the door. The new vendor is still learning their supply chain, their machinery and so on so their resistors really do vary over 5%. Or maybe they screwed up their initial calibration and all of their resistors are -4% +/- 1%. Maybe they won't next year. But this year they do. It happens. Analogous things occur with other passive components, and especially with active components. The point of the example is that an unfortunately large number of designs unwittingly depend on parameters that are not part of the specification. This is why major vendors notify their large customers of process changes, even if the new parts will be made to the same specification. It gives a chance to make a lifetime buy, or try the new version before going into full production or whatever. When a grey market vendor labels a part incorrectly or fraudulently it violates this process, and has and will cause problems.

author: dmills
author_rank: Super Contributor
timestamp: August 27, 2015, 10:30:41 am
content: Yep, any given batch of grey market parts may be fine, but that does not help you as you never know that the NEXT batch will be like (And as I say, in most production you do not test components on an individual basis), this batch may be rejects because the offset voltage was out of tolerance which you don't care about, but maybe the next batch are rejects because of a problem with the thermal epoxy mounting the die to the lead frame, and 6 months down the line the failures will start....The cost of having to test (including life test!) unknown parts is so much greater then the additional cost of buying parts with a real manufacturer (and real batch traceability) behind them that it is just not worth the savings, this actually goes at least double for prototypes where you really need to be debugging the circuit not the parts!Now sometimes something goes on stupidly long leadtime (Maxim, looking at you!) and you have to use the grey market, but it is always a worry.Regards, Dan.