Counterfeit / Factory Reject LM386s?

[Paul Marossy]

I recently got a batch of LM386s from two different ebay sellers and ALL of them are crap... they don't work like they're supposed to - all I get is loud squealing, very loud weird noises and farting sounding oscillation if I do even get any signal going thru them. I'm beginning to believe these are counterfeits or factory rejects that somehow got into the public domain (Jameco). If I put the LM386s I got 12-14 years ago in the same circuit and they work just fine.

Has anyone else had this experience? At this point all I can say is WTF?

[Mark Hammer]

So, you ordered them from Jameco, or did you mean Jameco tossed them and someone resold them?

I imagine in each of my chip drawers there is at least one chip that I pulled from a perfed circuit that was misbehaving, and saved it because I didn't know for sure that the chip was bad.  Removal was just an incidental part of troubleshooting.

I probably should have taken my white paint-pen and stuck a dot on the underside of each of them, just to be able to identify them later.

[Paul Marossy]

So, you ordered them from Jameco, or did you mean Jameco tossed them and someone resold them?

I imagine in each of my chip drawers there is at least one chip that I pulled from a perfed circuit that was misbehaving, and saved it because I didn't know for sure that the chip was bad.  Removal was just an incidental part of troubleshooting.

I probably should have taken my white paint-pen and stuck a dot on the underside of each of them, just to be able to identify them later.

No, one of the sellers was Jameco. I bought 10 from them and five from a different seller and ALL 15 of them are crap.

[Govmnt_Lacky]

I work for an entity that purchases A LOT of electronics assemblies and parts.

I have been to 3 lectures THIS YEAR regarding the rampant problem with counterfeiting.

Catch my drift? 

It's bad!

[Paul Marossy]

I work for an entity that purchases A LOT of electronics assemblies and parts.

I have been to 3 lectures THIS YEAR regarding the rampant problem with counterfeiting.

Catch my drift? 

It's bad!

Argh. I was so mad for the last couple of weeks....  built the same circuit twice thinking it was my fault for all the weirdness, feeling like an idiot that can't do anything right and the whole time it was the damn fake or whatever the hell they are chips! Ridiculous (revolting, sad, infuriating, pathetic, annoying, disgusting) what people will do for a few bucks.

[Kipper4]

Yes it's sad mate.
Why don't you open a case with Ebay and get your money back at the least.
Chances are they will support you.

[Paul Marossy]

Yes it's sad mate.
Why don't you open a case with Ebay and get your money back at the least.
Chances are they will support you.

Not a bad idea.... but I have enough stress in every day life. I don't need to get shingles in my eye again, this time it will probably blind me in that eye. Anyway, this topic for sure is on my radar now!

[Rob Strand]

Yes it's sad mate.
Why don't you open a case with Ebay and get your money back at the least.
Chances are they will support you.

If no one says anything they will keep selling.

[reddesert]

Counterfeits are definitely a problem that people who manage electronics supply chains are concerned about. And it seems to me that counterfeits have become a problem in DIY, especially with end-of-life or rare-ish devices: BBDs, CA3080, through-hole JFETs.  It seems a little weird to counterfeit a chip as common as the LM386, though.  It also is strange to me that one would get problem ICs from Jameco; ebay is buyer-beware, but Jameco is a large supplier.  I would at least send them an email and ask if they've had any other reports of problems.

[Rob Strand]

t also is strange to me that one would get problem ICs from Jameco; ebay is buyer-beware, but Jameco is a large supplier. 

That's why it should be reported.   You don't know where it is in the chain unless it is investigated.  It could a dodgy supplier for Jameco or it could be dodgy employees in the warehouse or in shipping.  I remember a story were a genuine parts were swapped with fakes when the flight passed through China. Everything looked legit except the parts!  It takes organization, probably at the source,  to pull something like that.

[MrStab]

hi Paul,

just out of curiosity: do they work in op-amp circuits? just asking as there are only a handful of 8-pin power amp IC's i know of and i don't think they're pin-compatible, so maybe they're just a bunch of crap op-amps.

i know there are TDA* chips which offer better performance than the 386, but is there anything cheaper on the (legit) market?

[Rob Strand]

No, one of the sellers was Jameco. I bought 10 from them and five from a different seller and ALL 15 of them are crap.

Make sure your circuit meets all the requirements of the datasheet, like the Zobel network.  If it doesn't, one day, perhaps today, the circuit will misbehave even though it didn't before.   Moreover when it does misbehave like this it is likely to do the same on chips of the same batch.

Bypass caps on the supply and issue with grounding are also possible conditions which cause oscillation and the symptoms you see.  If not enforced in the datasheet these are upto the designer so it's hard to determine the blame unless you try it on a 100% clean layout.

[Rob Strand]

I found this,

https://hackaday.com/2017/07/15/lets-play-spot-the-fake-mosfet/

Go half-way down
" Wolf says:   
July 15, 2017 at 9:41 am "

[Paul Marossy]

No, one of the sellers was Jameco. I bought 10 from them and five from a different seller and ALL 15 of them are crap.

Make sure your circuit meets all the requirements of the datasheet, like the Zobel network.  If it doesn't, one day, perhaps today, the circuit will misbehave even though it didn't before.   Moreover when it does misbehave like this it is likely to do the same on chips of the same batch.

Bypass caps on the supply and issue with grounding are also possible conditions which cause oscillation and the symptoms you see.  If not enforced in the datasheet these are up to the designer so it's hard to determine the blame unless you try it on a 100% clean layout.

Two different builds, same circuit, same results. If I use my LM386s from 12-14 years ago it works just fine. When I put these "new" ones in the circuit they become completely unusable. So that leads me to believe that either the LM386s are fakes, factory rejects, or they have significantly changed the internals of the chip so that it no longer works in the circuit as designed. The circuit follows the data sheet and it's running on 9V. The data sheet seems to be the same as it was say 10 years ago. If the chips were to spec I should be having none of these problems.

[Paul Marossy]

hi Paul,

just out of curiosity: do they work in op-amp circuits? just asking as there are only a handful of 8-pin power amp IC's i know of and i don't think they're pin-compatible, so maybe they're just a bunch of crap op-amps.

i know there are TDA* chips which offer better performance than the 386, but is there anything cheaper on the (legit) market?

I had a thought that maybe they're opamps marked as LM386s but I haven't tested that theory.

[Paul Marossy]

Counterfeits are definitely a problem that people who manage electronics supply chains are concerned about. And it seems to me that counterfeits have become a problem in DIY, especially with end-of-life or rare-ish devices: BBDs, CA3080, through-hole JFETs.  It seems a little weird to counterfeit a chip as common as the LM386, though.

I'm aware of the counterfeiting with BBDs, etc. Some people seem to think that the LM386s are now obsolete and they will be going away. Or at least maybe that's the belief in counterfieitland? I dunno.

[Electron Tornado]

Paul, you should contact Jameco directly. Being a large and reputable business, they would want to know if there is a problem with any of the parts they sell. Hopefully, they would send you some real 386s.

Since you bought from Jameco through ebay, do you recall where it said the items would be shipped from?

[Paul Marossy]

Paul, you should contact Jameco directly. Being a large and reputable business, they would want to know if there is a problem with any of the parts they sell. Hopefully, they would send you some real 386s.

Since you bought from Jameco through ebay, do you recall where it said the items would be shipped from?

I have the envelope it was mailed in, but I'm at work right now. Here is a link to the ebay page: https://www.ebay.com/itm/Texas-Instruments-LM386N-1-NOPB-Audio-Amp-Single-Speaker-1-Channel-Mono-0-10-pcs/112229787423?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

[MrStab]

conspiracy theory: Jameco banks on the increased difficulty of raising complaints (and subsequently less harm to reputation) facilitated by eBay, and gets rid of known-counterfeit goods there?

they could at least get one decent image of a generic DIP8 IC. i know it's superficial, but i've rejected sellers based on the half-assedness of their images. you'd look past that when it's a brand everyone recognises like Jameco, though.

[Govmnt_Lacky]

Paul... if you are in a bind and need some LM386s, let me know. I am 99% sure I have some around with no plans for use.

(Not sure if they are -1 or -4 though)