Fake chips? - Page 1
Forum section: electronics / general

author: NivagSwerdna
author_rank: Super Contributor
timestamp: May 20, 2018, 08:52:24 am
content: Whilst fixing my Symmetricom GPSDO I encountered a circumstance where a cheapo RS232 Level converter got finger burning hot and I had assumed that this was because of a failure elsewhere in circuit (which there was...). Anyway I fixed the original problem and swapped out the Level converter and all appeared fine until about six hours of operation later the RS232 goes deaf and again my RS232 level converter is super hot.Have I been afflicted by fake MAX3232s?I see someone had a related experience here...https://blog.heypete.com/2016/09/11/investigating-fake-max3232-ttl-to-rs-232-chips/If so this is the first time I have been burned (literally) by fakes!

author: Burczyk
author_rank: Contributor
timestamp: May 20, 2018, 05:31:07 pm
content: Did you order them from china/vietnam/singapore? Just asking

author: rstofer
author_rank: Super Contributor
timestamp: May 20, 2018, 08:06:19 pm
content: I think it is pretty well established that buying chips from China carries a risk. The real issue is how you price your time.My time is worth $100/hour (just a number I grabbed out of the air, nobody in their right mind would pay me that!) so everything I do is based on time and money. There is no way I can use up labor at $100/hr to troubleshoot what I wouldn't have to troubleshoot if I paid a few dollars more and bought the parts from DigiKey.The MAX3232 is about $7 at DigiKey and something for shipping. It wouldn't be the only thing I order so I'll just not worry about Priority Mail. For $7 vs $1, I can only spend about 3.6 minutes troubleshooting for the wee bit of savings.Not worth the aggravation!

author: NivagSwerdna
author_rank: Super Contributor
timestamp: May 20, 2018, 08:33:20 pm
content: Quote from: Burczyk on May 20, 2018, 05:31:07 pmYeap these are from China. 10 pieces for £1.53. Bargain.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: May 20, 2018, 08:50:56 pm
content: Aha!https://www.eevblog.com/forum/reviews/fake-max3232-any-additional-details/there was a thread here already!

author: BrianHG
author_rank: Super Contributor
timestamp: May 20, 2018, 10:41:25 pm
content: I'm sorry, but they are 2.01$ at Digikey, 1.67$ from TI, 1.65$ at Arrow, $1.29 at Avenet for 1 new authentic one. Cost less if you purchase multiple ICs.

author: Bassman59
author_rank: Super Contributor
timestamp: May 20, 2018, 11:20:40 pm
content: Quote from: BrianHG on May 20, 2018, 10:41:25 pmSo this is all in favor of buying name brand parts from established, reputable distributors, and not unknown crap from Alibaba or eBay. I agree!

author: NivagSwerdna
author_rank: Super Contributor
timestamp: May 21, 2018, 08:53:01 am
content: You lot are so grumpy! This isn't for a commercial product it's for home tinkering. And for home tinkering the China sourced eBay stuff is definitely the cheapest way to go especially if you accept there is a certain failure/fake rate.Incidentally I do have some legit TI MAX3232 somewhere.. I'lll dig one one and compare and contrast when I have time.I'm quite interested in the failure mode of these things... it definitely works for a while but i'm hammering it with continuous traffic.. maybe that pushes it over the edge.

author: xaxaxa
author_rank: Regular Contributor
timestamp: May 21, 2018, 05:18:17 pm
content: ironically it's usually the jellybean simple ICs that tend to be defective; I have bought everything from high speed ADCs to FPGAs to RF synthesizers to RF power LDMOS transistors from aliexpress/taobao over the years and either never got a fake or just got really good fakes; everything I could measure are always within spec and parts never fail long term. otoh I ordered some 78L05 voltage regulators and all explode when you apply 26V (which is within limits) to the input. Connectors (of any kind) from aliexpress also tend to be bad.

author: Yansi
author_rank: Super Contributor
timestamp: May 21, 2018, 05:44:43 pm
content: Quote from: blueskull on May 20, 2018, 08:30:26 pmWhy not the STM one? (ST232 or ST3232)

author: tsman
author_rank: Frequent Contributor
timestamp: May 21, 2018, 06:48:22 pm
content: Quote from: xaxaxa on May 21, 2018, 05:18:17 pmMy experience with those kinds of chips is that they're usually authentic but it is luck of the draw if you get good chips. The problem is that there are a lot of refurbished pulls from recycled boards mixed in with actually new chips. Whatever process they use to desolder the chips appears to be brute force with high temperatures.

author: nctnico
author_rank: Super Contributor
timestamp: May 21, 2018, 07:04:04 pm
content: Quote from: blueskull on May 20, 2018, 08:30:26 pmAn A brand like ST or TI is a good choice but anything from Sipex is utter rubbish as well.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: June 14, 2018, 05:49:16 pm
content: Eventually got around to looking at the GPSDO again so swapped the chip on the cheapo breakout board for one I had direct from TI.Incidentally I measured the caps on the board and they all appear OK and around 100nFWorking again now. I think I have learnt my lesson on those boards.

author: Beamin
author_rank: Super Contributor
timestamp: June 14, 2018, 06:02:59 pm
content: If the fake works what is the difference; I mean literally what makes it different physically? Do they not test the chips and sell all they make vs TI will test and throw away a %?Do the fake makers steal the picture of the chip and feed it into a silicon die making machine? Not like a car where there are any parts there are the chip wires legs and plastic.

author: wraper
author_rank: Unknown
timestamp: June 14, 2018, 06:05:50 pm
content: Quote from: Beamin on June 14, 2018, 06:02:59 pmFakes often work but usually either not exactly the same and/or are not reliable.QuoteIt was sort of true when Soviets cloned SN7400 series. Not the case today, you get completely different silicon die inside.https://zeptobars.com/en/read/Ti-555-NE555-real-vs-face-china-chineseAs well you may get some similar IC with fake marking. Pinout may be the same but IC itself quiet different but appear to work in many cases. That's why it's very risky to buy any opamps from China.

author: Beamin
author_rank: Super Contributor
timestamp: June 14, 2018, 06:45:13 pm
content: This is from some other thread long ago but very interesting:http://www.asq.org/asd/2009/03/compliance/counterfeit-parts.pdfWill intel or AMD hand wash your chips in pure river water and hand dry them in the sunshine for you? Or deliver by hand (bicycle) in humidity controlled rice sacks where the humidity is controlled by god(great weather of Shenzhen)? I don't think so. That's why I buy Chinese chips they are all natural, organic, baked in the sunshine, not an oven by humans not machines.I think JDOE does an excellent job as operator to pack them too!

author: NivagSwerdna
author_rank: Super Contributor
timestamp: June 14, 2018, 07:03:24 pm
content: Quote from: Beamin on June 14, 2018, 06:02:59 pmBut they don't. They work for a short time and then go deaf and overheat.

author: Beamin
author_rank: Super Contributor
timestamp: June 18, 2018, 01:14:13 pm
content: Quote from: NivagSwerdna on June 14, 2018, 07:03:24 pmSo normal operation for something you buy at Walmart or radio shack.

author: Canis Dirus Leidy
author_rank: Regular Contributor
timestamp: June 18, 2018, 03:02:20 pm
content: Quote from: Beamin on June 14, 2018, 06:02:59 pmIn the details, like any other devil. Yes, it's works and don't burn right away when you turn it on. But then you dig deeper and its turn out that cheap opamp from Aliexpress is much more noisy (likethis"OPA627") or not so fast (this"LM6172", supposedly remarked NE5532).

author: schmitt trigger
author_rank: Super Contributor
timestamp: June 18, 2018, 03:29:06 pm
content: Quote from: Beamin on June 14, 2018, 06:45:13 pmYou forgot to mention that these chips are only harvested under full moons, and/or when Sagittarius is aligned with Jupiter.

author: schmitt trigger
author_rank: Super Contributor
timestamp: June 18, 2018, 03:59:08 pm
content: Quote from: NivagSwerdna on May 21, 2018, 08:53:01 amAs others have already mentioned, why go thru all the aggravation and waste of time?When I build a product for tinkering, I DO EXPECT that I will have to spend time troubleshooting the unit. The lessons in life are learned by resolving problems and failures.And one of the important lessons I've learned, is that if the price is too good to be true, then it is not true!

author: @rt
author_rank: Super Contributor
timestamp: June 18, 2018, 07:45:13 pm
content: The last chip one of my hobby projects was focussed around was fake.I had an original as well, and as soon as it went in the same socket all was well.The messing about wasn’t worth it for sure.It wasn’t any kind of real chip at all, but at least not shorted legs.The encapsulation contained a piece of sheet metal that just wasn’tconnected to any of the IC legs thankfully.

author: GreyWoolfe
author_rank: Unknown
timestamp: June 18, 2018, 08:55:46 pm
content: Quote from: schmitt trigger on June 18, 2018, 03:29:06 pmAnd harvested by nubile nude virgins supervised by by greybearded 10th degree Grandmasters.

author: Beamin
author_rank: Super Contributor
timestamp: June 24, 2018, 03:35:54 am
content: Quote from: @rt on June 18, 2018, 07:45:13 pmAnd you found this to be a problem why? I wonder why they even bothered to put in the metal not like many people go around xraying things. Well if I had an xray machine I would use it all the time.Maybe the river they washed the chips in was polluted with arsenic and this is how they dope chips in china. Mmmmmm arsenic...<- homer simpson head

author: schmitt trigger
author_rank: Super Contributor
timestamp: June 25, 2018, 01:10:08 pm
content: The arsenic-laden rivers are reserved for fishing.

author: Beamin
author_rank: Super Contributor
timestamp: July 21, 2018, 03:56:16 am
content: Quote from: schmitt trigger on June 25, 2018, 01:10:08 pmBathing washing and drinking. Good source of water for Chinese baby milk formula too! In poorer communities in the US where fluorinated tap water is used for baby formula results in higher crime and learning disabilities. Distilled water is $1.00 a gallon. The baby doesn't drink that much how can you ruin your kids life by not spending an extra dollar? I know people are stupid but I remember my families kids always using distilled water for formula, it must say this on the box of formula.