There's numerous instances where inexperienced users bought things off the internet that didn't come with anything resembling sufficient documentation, often even of very basic things like operating voltages, and expect us to compensate for the shortcoming of the seller.

I think we should not tolerate these kinds of questions for (at least) two reasons:

  • Politically, and economically, it's unsound to support business models where people of no technical expertise whatsoever sell components on the internet, getting around having to actually afford documenting their parts, whereas companies that actually do offer even the minimum feasible documentation have expenses. This is made morally worse by the fact that "clones" and plain counterfeits that don't even incur any R&D costs are among the things that are most heavily sold in this form.
  • It's bad for the quality of questions on this site. Basically, the same reasoning as against product recommendation questions apply: Information outdates quickly, this isn't a catalogue, the questions are usually underresearched.

Finally, I also do think it's bad for beginners. If I accumulate my experiences with things that people have bought over {insert direct far-east import marketplace platform here}, it's that these things seldom work as well as to expect from a reasonably engineered and quality-assured product, and that's usually the reason why the price tag's so low.

Beginners are led to believe that not getting the specs of what they pay for from whoever they pay is the norm. And that should really not be the case. And, if we don't proliferate quickly outdated info based on guessing on (usually actually stolen) product photos, we can at least avoid giving this impression a platform.


Can we please have a close reason

I'm voting to close this question as off-topic, as StackExchange should not be used as substitute for sufficient documentation. Please refer to the manufacturer, seller or service dealer for sufficient documentation, as is the standard for any reputable business.

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    \$\begingroup\$ That is a bit too specific, we could then come up with a lot of more similar reasons, not for parts but for whole systems, existing PCBs etc. so if at all I think such a reason should be somewhat broader. \$\endgroup\$ – PlasmaHH Jan 23 '18 at 13:52
  • \$\begingroup\$ good point – I'll edit this, as I'm clearly not disrupting an existing discussion with an edit :) \$\endgroup\$ – Marcus Müller Jan 23 '18 at 13:52
  • \$\begingroup\$ better now, @PlasmaHH? \$\endgroup\$ – Marcus Müller Jan 23 '18 at 13:56
  • \$\begingroup\$ definetly. Now I will go think about if we have enough of those to warrant a new close reason. \$\endgroup\$ – PlasmaHH Jan 23 '18 at 13:57
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    \$\begingroup\$ I've added it to the informal list of templates for reoccurring close reasons. \$\endgroup\$ – Nick Alexeev Jan 23 '18 at 18:36
  • \$\begingroup\$ Thanks! That's definitely valuable. \$\endgroup\$ – Marcus Müller Jan 23 '18 at 20:43
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    \$\begingroup\$ @NickAlexeev thanks for sharing that.... another hidden gem :) \$\endgroup\$ – Trevor_G Jan 25 '18 at 20:11
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    \$\begingroup\$ Sorry Marcus -1 for bringing Politics into this. It is not why we are here. We are just here to match a lack of knowledge with available knowledge for the future. I am against most close reasons for questions that have (a hope for) an answer as answers are what electronic.stackexchange is really about. \$\endgroup\$ – KalleMP Jan 28 '18 at 18:28
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    \$\begingroup\$ @KalleMP don't be sorry! I think your opinion is a valid one, and if I wasn't looking for counterarguments, I wouldn't have posed the question as I did. And: I certainly don't feel immediate pain if someone disagrees with me, and even less so if they downvote a Meta.SE question of mine :) \$\endgroup\$ – Marcus Müller Jan 28 '18 at 18:42
  • \$\begingroup\$ (hey, @oldfart, I've reverted your edit – I might not be a native speaker, but isn't it "SE should not be a substitute for {what you actually need}" instead of "SE should not be a subsitute for {what you don't need}"?) \$\endgroup\$ – Marcus Müller Jan 28 '18 at 18:47
  • \$\begingroup\$ @MarcusMüller Nope, I am pretty sure it should be "insufficient" otherwise I never would have dared to touch your text. Why don't we throw it at the English language stack exchange? \$\endgroup\$ – Oldfart Jan 28 '18 at 19:06
  • \$\begingroup\$ we could, but to give you an example: "SE shouldn't be a substitute for happiness" makes a lot more sense than "SE shouldn't be a substitute for pain". \$\endgroup\$ – Marcus Müller Jan 28 '18 at 19:19
  • \$\begingroup\$ "Substitute: a person or thing acting or serving in place of another." So you substitute A for B where you have an A and you have a B. You take out B and put A in place. A is SE stack-exchange. B is insufficient data sheet. There is no negation in there. Your examples above are both correct but in one case you have happiness and the other case you have pain. That you are more likely to be happy than have pain is insubstantial. \$\endgroup\$ – Oldfart Jan 28 '18 at 19:31
  • \$\begingroup\$ @oldfart But in this case, B is the hypothetical "sufficient data sheet" that doesn't exist, and so Stack Exchange is being used in lieu of it. (Am native speaker, am not proud of it.) \$\endgroup\$ – wizzwizz4 Jan 28 '18 at 19:32
  • \$\begingroup\$ Please add some examples of these questions to your post. \$\endgroup\$ – user253751 Jan 28 '18 at 23:47

I completely understand your position but disagree.

I don't see why those of like mind can't simply ignore the question if it's of no interest.

Championing the active prevention of the posting and answering of what are most certainly widely useful answers for the stated reasons seems heavy-handed in a central-planning sort of way.

If there was a 'hobby' SE that might make sense to shunt questions off to there, but there isn't and there are a bunch of presumably similarly (but differently) annoying questions that arise from bad youtube videos, instructables and such like.

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    \$\begingroup\$ +1 but "If there was a 'hobby' SE that might make sense to shunt questions off to there" but then it would get boring pretty quick.... I'd miss the "chicken-coop-doors" and what not ;) \$\endgroup\$ – Trevor_G Jan 25 '18 at 20:09
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    \$\begingroup\$ "I don't see why those of like mind can't simply ignore the question if it's of no interest." Wouldn't that apply equally to questions about flower-arranging? \$\endgroup\$ – David Richerby Jan 28 '18 at 17:42
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    \$\begingroup\$ @DavidRicherby Flower arranging has nothing to do with electronics, does not generally involve knowledge or love of the profession or the hobby of electronics, and there are doubtless more appropriate SE sites for enthusiasts of Ikebana or whatever. If someone starts applying electronics in some way to flower arranging, sure, why not? \$\endgroup\$ – Spehro Pefhany Jan 28 '18 at 19:28
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    \$\begingroup\$ Sure, but the point of the discussion is to define what is and is not on-topic. "If you're not interested, ignore it" applies equally well to on-topic, borderline/debatable and off-topic material (e.g., electronics, support for undocumented components and flower-arranging, respectively), so it's not actually an argument for or against any position that subject X should be on-topic. \$\endgroup\$ – David Richerby Jan 28 '18 at 19:38
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    \$\begingroup\$ @SpehroPefhany I tried but the best I could find was - instructables.com/id/Flower-Dome-Retro-Module \$\endgroup\$ – KalleMP Jan 28 '18 at 19:43
  • \$\begingroup\$ Questions of this nature are explicitly on-topic at Reverse Engineering. And really, how many hobbyist sites do we need? reverseengineering.stackexchange.com diy.stackexchange.com hardwarerecs.stackexchange.com android.stackexchange.com lifehacks.stackexchange.com retrocomputing.stackexchange.com Why must we make EE a hobbyist site also? \$\endgroup\$ – Lundin Jan 30 '18 at 16:21
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    \$\begingroup\$ @Lundin One reason is that there would not be very many questions otherwise. The vast majority of questions appear to be from either hobbyists/tinkerers or students. Part of my tolerance for such questions is that I remember learning from surplus equipment for which no information was available. Accessing proper data sheets was a hassle or impossible (data books were handed out by physical sales people who vetted the recipient), and some of the stuff was old (Vietnam or even WWII war surplus). \$\endgroup\$ – Spehro Pefhany Jan 30 '18 at 19:37
  • \$\begingroup\$ @Lundin "Why must we make EE a hobbyist site also?". As long as I can remember (I wasn't a site user since beta stage) EE.SE is a site that appealed to both professionals and hackers from the very beginning. Part of what made EE.SE successful (one of the SE site with the highest signal/noise ratio, also acknowledged by SE staff not long ago) is the combination of broad audience (which include non-professionals) together with somewhat harsh moderation. A bad question will be "filtered out" whether or not it comes from a professional, a student or a hacker. \$\endgroup\$ – Lorenzo Donati -- Codidact.com Feb 2 '18 at 6:00
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    \$\begingroup\$ This exactly. The idea of getting something cool or unusual and getting some help figuring it out is a BIG part of the community. Getting all political and "you should only buy parts from Name Brand Vendors" has some pretty serious side effects. \$\endgroup\$ – akohlsmith Feb 3 '18 at 14:54
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    \$\begingroup\$ @Lundin reversengineering is all about sw RE and hardwarerecs is far too broad to encompass the relatively few directly-relating-to-electronics questions of this specific nature that we get here. And let's be perfectly serious here and put aside the pomp; e.se is not a "professional" site by any stretch of the imagination. It's by hobbyists, for hobbyists. While a good deal of us here are professionals, I would prefer to not try and impose some kind of cathedral-like hierarchy and pretence to what is a very useful and helpful site for everyone. \$\endgroup\$ – akohlsmith Feb 3 '18 at 14:59

Sorry, but I strongly disagree.

By putting all the cheap stuff found on eBay and Amazon or other "non reputable" sources into the same thrash bin is judgemental and heavily penalizes low-income hobbyists, especially those in developing countries.

I still remember when I disassembled old TV sets to get scrap components when I was a young boy. If I had had such sources at the time I could have made great projects with a couple of bucks and I could have learned much more quickly. Instead, all my money went into the few things I couldn't get from scrap equipment (e.g. a good analog multimeter).

Moreover, although some modules and components are not well specced (or no specced at all), they are not necessarily total crap. I'm currently testing a small Arduino mini pro compatible board (2 EUR) driving fancy patterns on a cheap SPI-controlled display module. It has been running that routine for about 7 month now (I really wanted to see if they were worth at least a tenth of their price). Guess what? Never a glitch! Of course I wouldn't trust it for mission-critical stuff nor for professional devices, but for learning and hobby projects they are great.

I even tested a batch of probably fake "el cheapo" 1N4007 diodes (their terminals were tiny as those of 1N4148s): they performed quite well and the DC characteristics were in line with the datasheets of major vendors (I wouldn't trust them for peak non-repetitive currents of tens of amps, like the "real ones", but for hobby work, heck!, they cost a tenth of the price and you won't regret frying a dozen of them while learning!)

Yes, I know it's an hit and miss and you can find really crappy stuff out there. However, if you find the right vendors, they usually keep their quality standards quite predictable across their goods.

I agree that we should always point out that there are higher standards in professional electronics, so that the beginner has a chance to learn and improve, but not every hobbyist will be a future electronic designer or engineer.

Therefore I think that we should respect those who infuse sufficient effort in asking a question, even if they use components of unknown source, and we should not dismiss their questions for their lack of money or resources.

As I always remind people on this site, this is not (yet?!?) a "professionals-only site". If we are to keep our policies that way, we must cope with people who sincerely love electronics and want to do more advanced projects with less money, instead of always flashing an expensive Cree LED using a couple of original Fairchild BC547s or whatever /grin/.

The scale of the economics is 1 to 10, or more, sometimes! You can't really blame a poor newbie because (s)he prefers to program a cheap Arduino clone. We are not here (at least, I am not) to protect the interests of TI, Vishay or Nexperia against hobbyists eroding their profits by not buying original parts. I'm not getting paid by them, so I owe them nothing, except due credit for making exceptional stuff, and this also means telling an hobbyists what's the difference between quality and crappy stuff (and between professional stuff and hobby work).


Since my answer has drawn much attention and is currently the highest ranking one in this thread, I'd like to point out better why I think hobbyists are a resource for this site even if they don't follow professional best practices.

See this question posted some time ago. What on earth could be less professional than that by today's standards! This notwithstanding, that question was well posed and slightly humorous (and the OP was very responsive in comments), and this prompted many good answers that covered many aspects that are relevant even for a professional.

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    \$\begingroup\$ As I always remind people on this site, this is not (yet?!?) a "professionals-only site". If we are to keep our policies that way, we must cope with people who sincerely love electronics and want do more advanced projects with less money, instead of always flashing an expensive Cree LED using a couple of original Fairchild BC547s or whatever /grin/. THIS. \$\endgroup\$ – Passerby Jan 28 '18 at 0:52
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    \$\begingroup\$ The site is nowadays called Electrical Engineering. That implies a certain level of professionalism and knowledge. There's a certain difference between clueless hobbyists and clueless students here. The clueless hobbyist is doing things wrong because they aren't interested in best practices and they use a limited budget, taking shortcuts because of it. While the clueless student is doing things wrong because they do not know better, but at least they have an ambition to learn the correct and professional way. \$\endgroup\$ – Lundin Jan 30 '18 at 16:07
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    \$\begingroup\$ @Lundin "hat implies a certain level of professionalism and knowledge." Sorry, your view is wrong, according to the site help center and community conventional wisdom. (Limited-budget) enthusiasts and hackers are welcome here. The fact that the site is called EE is not due to the fact that we want to target only (prospective) professionals, but not to exclude them. We do want professionals here, so we must appeal to them, and this is done through permeating the site with "pushes" toward professionalism, also through a somewhat harsh moderation.... \$\endgroup\$ – Lorenzo Donati -- Codidact.com Jan 31 '18 at 4:19
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    \$\begingroup\$ @Lundin ... We want quality questions and answers, we do not want knowledge (or worse) economic elitism. As I stated in my answer, not every enthusiast will (or wants to, or is to) become an engineer, and we don't want to exclude this kind of persons. \$\endgroup\$ – Lorenzo Donati -- Codidact.com Jan 31 '18 at 4:22
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    \$\begingroup\$ @Lundin Moreover, determined low-budget enthusiasts can express the true essence of an engineer: solve problems in creative ways using the limited resources at their disposal. Throwing more money at a problem is a more "top-manager view". Of course a professional will have learned the tricks of the trade and will avoid crap and such stuff when doing serious professional work. It is more educative to help people solve their problem, if possible - sometimes the only answer is "your gear is too crappy for what you are attempting to do", but then explaining why the gear is too crappy! \$\endgroup\$ – Lorenzo Donati -- Codidact.com Jan 31 '18 at 4:32
  • \$\begingroup\$ Regarding the budget aspect it is often "I bought this radio thingie from aligarbage.com and nothing works. I already spent all of my budget on this", because they didn't know the right channels (ie the normal electronics distributors) to use for purchasing a much higher quality product from nearly the same price. And then with shopping recommendations being off-topic, there's no help to be found here either. \$\endgroup\$ – Lundin Jan 31 '18 at 7:43
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    \$\begingroup\$ "I still remember when I disassembled old TV sets to get scrap components when I was a young boy". You and me both. And the effort of figuring out what I had just salvaged, long before the internet was even invented... \$\endgroup\$ – Floris Jan 31 '18 at 17:08
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    \$\begingroup\$ @Lundin no, "electrical engineering" does not imply a certain level of professionalism and knowledge. It implies an interest and desire to practise the art and science of electrical engineering. I've been doing this professionally for 22 years now and am able to afford a comfortable life from my skills gained over this time. Are you implying I should not be able to do this because I do not have the degree and iron ring? \$\endgroup\$ – akohlsmith Feb 3 '18 at 15:02

I partially agree with your sentiment, but I disagree on a few points:

  • As a Q&A site, our goal should be to share our knowledge with 'the internet', so in principle whatever we share could be beneficial to someone. We shouldn't be judgemental of what their reasons could be.

  • The lack of documentation could also be caused by obsolescence or any other reason, and the close reason might look to someone as a quick way to dismiss a possibly valid question.

  • What you say about investment in documentation, I think it's not our responsibility to support one or the other business model. We try to help the engineers and hackers (in general: users) community by providing the necessary information.

We can also choose to inform beginners that a certain piece of equipment may not be a wise choice, but in the end it is their business whether they use it or not.

  • \$\begingroup\$ Thanks! I don't think your second point is 100% fair, though: I don't think any of our close reasons are assuming bad faith! But you're very right, the close reason should make clear that it's fair, for the type of product/service OP asked about, to expect whoever's making the money to supply documentation; this should not be a catch-all for things like "cross usage" or obscure parts (think: vacuum tubes), where it's not to be expected that a seller would even have access to documentation. \$\endgroup\$ – Marcus Müller Jan 23 '18 at 13:59
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    \$\begingroup\$ @MarcusMüller Indeed that second point looks harsh to me too, I'll try to reword it \$\endgroup\$ – clabacchio Jan 23 '18 at 14:07
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    \$\begingroup\$ Thanks! Like it much more now! \$\endgroup\$ – Marcus Müller Jan 23 '18 at 15:02

Cheap (and often undocummented well) stuff from popular online marketplaces is not neccesseraly crap. More expensive brand name goods are usually just a better probability it's not crap (just have a look at some errata pages in the popular datasheets).

BUT too often the only way to find out if the noname stuff is of poor quality and not clear how to deal with OR just less fancy but fully compatible with industry standards and behaves in expected way IS to try.

I know people who have access to high-end equipment and materials but occassionaly buy cheap stuff just for fun. If that doesn't function or is too cumbersome to make it work it's no big deal to dump it right away. But if that appears a fair thing for the price this means they get some experience.

But how would they share it if it's banned? :-)


It might be better to ask a question like

"Why is it a bad idea to buy crap from e-bay." in the forum, and have people answer it well so you can cross-post that in those type of questions.

That way it is more edu-ma-cational...

Actually there are a few "often up" questions like that. We could really do with a common library question pages. Like...

"500 ways to drive a LED from a GPIO..."

Pity those type of questions are deemed... not questions.

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    \$\begingroup\$ You misspelled edja-muh-cayshunal ;o) \$\endgroup\$ – Will Crawford Jan 26 '18 at 15:47
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    \$\begingroup\$ so, I was really close to accepting this answer. In all honest, why did I not have a self-answered question of the like "I'm about to buy an attractively priced article, but the seller doesn't offer much info. What should I know before I do the purchase?", with an answer that centers around an example of something that can actually also be bought with documentation, the difference it makes, a screenshot of what a "normal" product page looks like, maybe a (redacted) excerpt from an actual conversation with a distributor, and a TCOO calculation including risk. \$\endgroup\$ – Marcus Müller Jan 30 '18 at 17:42

I disagree that we should banish all things Ebay or otherwise. We do have the option to close out the OP in a hurry if it is that bad.

Speaking of bad, what concerns me more is an OP with little to no skills who wants to build a Tesla coil from an Ebay power supply. That is like trouble squared.

Yet in spite of that often and dreadful combination I do not think we should just close because of poor or missing documentation alone. They are many hobbyist who know the pin-outs of many IC's by heart-like me. And may have spent decades building this-and-that, so they do not mind hand-me-down parts from Ebay or other parts brokers with high prices.

What we should question the most is does the OP know what they are doing? The worst case scenario is the OP knows little and has no documentation. From there it gets a little better. Does the OP have documentation to present to us but lacks skills? Does the OP have much skill but is missing a detail or an understanding of a dubious spec?

The variations I have seen in just a few years suggest that we continue as is and let the close/re-open and migrate system take out the garbage too messed up to work with. This includes what seems to be a good question and documentation but a stubborn OP who does not cooperate with us, such as providing us with a diagram or schematic.

The close option gives us the option categories we need to take the garbage out of the system, sometimes in one day.

I see NO point in putting a noose around the OP's neck just for lack of documents. We must judge such events based on the OP's skill (or lack of) as well.

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    \$\begingroup\$ Downvotes here on meta just means "Meh, I don't think this is the way to go", not "This answer sucks". It doesn't affect your score. \$\endgroup\$ – pipe Feb 2 '18 at 12:03

The scope of EE is already incredibly broad, it wouldn't hurt to narrow it down a bit.

I propose that we make questions of the nature described by the OP off-topic, but direct them to Reverse Engineering instead. It seems to be the perfect fit for these kind of questions.

This with the blessing of that site, of course, though I doubt a SE beta site would mind getting more visitors.

  • \$\begingroup\$ Though I like the idea of showing people that, hey, instead of reading a datasheet, they are now actually already in the process of reverse engineering something, I kind of doubt RE.SE would be eager to take up "hey, I really can't tell a diode from a hammer, but I bought this 7-segment display and wonder how to control it with these unlabeled 5-wire cable" questions. The "I've already showed I've done my fair share of research into the inner workings, and my buy was one well-aware of the fact that I'll need to do this" case isn't really what I was aiming for :) \$\endgroup\$ – Marcus Müller Jan 30 '18 at 17:36
  • \$\begingroup\$ Sorry, but that could be wrong site, really. From their tour page (emphasis mine): Reverse Engineering Stack Exchange is a question and answer site for researchers and developers who explore the principles of a computer system through analysis of its structure, function, and operation. So it is explicitly targeted at: (1) professionals, (2) computer systems (so no opamps there!). No "hackers", "makers" or "enthusiasts" mentioned. \$\endgroup\$ – Lorenzo Donati -- Codidact.com Feb 1 '18 at 4:18
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    \$\begingroup\$ @LorenzoDonati There's a reason why I linked to the site's "on-topic" page, where one example of a valid topic is "hardware analysis and testing". That's the case here. \$\endgroup\$ – Lundin Feb 1 '18 at 8:02
  • \$\begingroup\$ @Lundin I saw that, but I didn't question the appropriateness of the subject (except that it is limited to computer systems, not general electronics, which is explicitly stated), but the level of competence required from the asker. Anyway, I posted a question on meta RE.SE. Let's see what they say. \$\endgroup\$ – Lorenzo Donati -- Codidact.com Feb 1 '18 at 19:01

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