Authenticity of chips from China, and markings - Page 1
Forum section: electronics / general

author: lpc32
author_rank: Frequent Contributor
timestamp: December 30, 2020, 09:19:51 pm
content: What's your opinion and experience with the authenticity of basic chips bought from China?I've noticed that some listings show chips without the manufacturer name marked, but according to user reviews the actual shipping chips do have it.On the other hand, some people complain about the lack of pin 1 dots.Indicates anything or just randomness?Some flash examples...Listingphoto without manufacturer mark (MXIC):A differentlisting. No MXIC in listing photo, and one user review mentions there's no pin 1 mark.But a photo in another user's review does show dots (and manufacturer name):Another listing, no manufacturer mark in listing photo:Manufacturer mark is present in a user uploaded photo, but the user complains about the pin 1 dot missing:

author: ataradov
author_rank: Super Contributor
timestamp: December 30, 2020, 09:43:34 pm
content: They often erase manufacturer logo, since they are not to not authorized distributors and don't want to deal with any issues. It is just easier that way. Plus they themselves may not know if stuff they are selling is fake. Or it may be fine one day and be fake the other day. Most of those stores don't really care. What would you expect from the store that also sells panties?It is virtually impossible to say what would be real and what fake. For memory, I would expect everything to be fake, since there are plenty of different designs that act the same exact way, so it is easy to package any random thing you find and mark it as a legitimate IC.For less commodity and more involved chips you get real ones more oftem.If I want China prices, but reasonable assurance, I use lcsc.com. I never had any issue with the stuff I got from them.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 30, 2020, 09:59:05 pm
content: If you buy on aliexpress at a bargain price - there are no guarantees. However, you can also buy cheap from a decent сhinese LCSC supplier.

author: thm_w
author_rank: Super Contributor
timestamp: December 30, 2020, 10:07:02 pm
content: Quote from: lpc32 on December 30, 2020, 09:19:51 pmPerson that made the photo doesn't seem to know that pin 1 is known from the silkscreen orientation. But anyway those first two ICs look to have been sanded down and remarked.You'll have to check the manufacturers datasheet to see if they give any specific pin/silkscreen markings. Genuine parts should match up with the datasheet, unless its old stock or something.LCSC has them for ~80c:https://lcsc.com/search?q=25q64

author: M4trix
author_rank: Frequent Contributor
timestamp: December 30, 2020, 10:14:17 pm
content: If the sanded chip doesn't have a dot that means you'll have to guess on which side was the dot. According to the Murphy's law,you will choose the wrong side.

author: thm_w
author_rank: Super Contributor
timestamp: December 30, 2020, 10:45:33 pm
content: Quote from: M4trix on December 30, 2020, 10:14:17 pmYou don't have to guess, its the bottom left side if you go based on orientation of the text.

author: schmitt trigger
author_rank: Super Contributor
timestamp: December 30, 2020, 11:16:56 pm
content: Is like going to a budget Bangkok brothel. You never know beforehand what are you getting into.

author: lpc32
author_rank: Frequent Contributor
timestamp: December 31, 2020, 01:32:55 am
content: Does the lack of pin 1 dot indicate inauthenticity?Didn't know about LCSC. May be interesting, but shipping's expensive for small orders, same as the big US suppliers.Taydaused to be a good middle-ground source, when their limited selection is enough. I haven't followed them recently, but right now it seems cheap shipping is no more, and it's roughly the same as the big suppliers. I don't know, maybe pandemic prices?BTW, they have a similar Winbond flash,though 128Mb, for $0.89.Quote from: thm_w on December 30, 2020, 10:07:02 pmHe likely does, just complains about authenticity.Quote from: M4trix on December 30, 2020, 10:14:17 pmAssuming it harms the chip. Even if so, you'd know after one try.Quote from: S. PetrukhinNo need to be sorry.

author: thm_w
author_rank: Super Contributor
timestamp: December 31, 2020, 08:14:42 pm
content: Quote from: lpc32 on December 31, 2020, 01:32:55 am"it is unknown where the first output of the chip is"