Happy New Year, everyone. If you built a new clock last year with a used or cheap DS3231, check the date to make sure it's correct.
I posted about this 2 years ago when I found another fake clock chip. On Friday, January 25, 2019 at 3:35:06 PM UTC-8 Tony Adams wrote: > There are indeed some strange 'counterfeits' around. Maybe they were a > deliberate attempt to confuse reverse engineering of some product, but > never used? or it could have been a simple mistake. > > I have a few thousand MPSA92 which have been remarked from MPSA42, > with the 4 and 9 superimposed. They work perfectly as PNP HV > transistors so it's possible somebody just forgot to change the > engraver text and the mistake wasn't noticed until they had a large > pile of mismarked PNP MPSA42s. > > Tony. > > On Fri, 25 Jan 2019 22:38:43 +0000, you wrote: > > >Hi Bill, > > > >Indeed, it seems bonkers. I assume it's because someone has a huge stash > >of open collector output 74 series shift registers, and either thinks > >they're the same, or that most people won't notice the difference. > > > >I bought two batches of 500 of them, from two different chinese suppliers, > >and they are all exactly the same, having the same laser engraved batch > >number even. To be fair, the prices were suspiciously good, but I wasn't > >banking on fake shift register ICs.... > > > >They are badged as TI SN74HC595N, and batch GM1807FSF. > > > >I have some 'normal' SN74HC595N, and swapping these out for the real ones > >generates the expected behaviour ( and yes, inv G is indeed pulled low). > > > >With the 'fake' ones, they will appear to work OK with a pull up resistor > >present (as you'd expect with an open collector output), but are unable to > >source any current. > > > >I thought it was just me, but then I googled GM1807FSF and found someone > >else (in German) having the same problem! > > > >https://www.mikrocontroller.net/topic/463936 > > > >David > > > >On Fri, 25 Jan 2019 at 22:24, Bill van Dijk <[email protected]> wrote: > > > >> That is really weird. Please understand I am not questioning what you > are > >> saying, but perhaps there is another explanation. The 74LS596 (I have > never > >> seen an HC version) is indeed an open collector chip similar to the > >> 74HC595, which is a tri-state device. On the 74HC595 the inv G (pin 13) > >> should be held low for normal operation. If it goes high for any reason, > >> the output will float in tri-state mode, similar to what an open > collector > >> would look like. As you say, I can’t for the life of me not figure why > >> anyone would bother to rebadge those chips especially since there does > not > >> seem to be an economic one (which is usually the motivation). > >> > >> > >> > >> Bill > >> > >> > >> > >> *From:* [email protected] [mailto:[email protected]] > *On > >> Behalf Of *David Pye > >> *Sent:* Friday, January 25, 2019 4:12 PM > >> *To:* [email protected] > >> *Subject:* Re: [neonixie-l] Re: Counterfeit RTC modules > >> > >> > >> > >> It seems even things barely worth faking are being faked also. > >> > >> > >> > >> I have a bag of 500 74HC595 shift registers, that are actually rebadged > >> 74HC596s (as in, open collector, SINK, not SOURCE-capable). > >> > >> > >> > >> Which are useless for my application :-( > >> > >> > >> > >> > >> > >> -- > >> You received this message because you are subscribed to the Google > Groups > >> "neonixie-l" group. > >> To unsubscribe from this group and stop receiving emails from it, send > an > >> email to [email protected]. > >> To post to this group, send email to [email protected]. > >> To view this discussion on the web, visit > >> > https://groups.google.com/d/msgid/neonixie-l/008501d4b4fc%24bb636a80%24322a3f80%24%40gmail.com > >> < > https://groups.google.com/d/msgid/neonixie-l/008501d4b4fc%24bb636a80%24322a3f80%24%40gmail.com?utm_medium=email&utm_source=footer > > > >> . > >> For more options, visit https://groups.google.com/d/optout. > >> > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/b53bebbb-c7e7-41ec-9b0a-bbb3e821d150n%40googlegroups.com.
