LM337: a new epidemic?

The power supply of my mckinnie pre-preamp died, so I bought a small 317/337 PS kit to replace it.
The negative leg didn't work, no biggy, I ordered a handful of LM337 from Aliexpress. All bad.
I ordered another small batch from eBay, Germany. All bad. It turned out they're the same items as Ali.
The prob appears to be some kind of a short between Vout and Adjust, so Vout is always ¦Vin¦ - 2V, regardless of the setting.
Out of curiosity, I ordered another batch from eBay China, but they've not arrived yet. We'll see if this is epidemic level.
Finally, I've got some NOS Motorola 337 from eBay France, and all is well.
I don't usually have problems with parts from Ali, but stay away from the 337 for now,

LM337-CN.jpg
LM337-bad.jpg
LM337-good.jpg
 
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Take a look inside your car: a lot of the parts are from "dubious places". And you're betting your life on them! :)
I worked in semiconductors (and electronic modules prior to that) supplying the auto industry. The reason a lot of mil spec has fallen away is because the auto industry pushed semiconductor quality to what it is today. There are no parts of dubious provenance in modern automobiles.
 
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... Not aware of Automotive buyers turning to Aliexpress?
... There are no parts of dubious provenance in modern automobiles.
I'm talking about the guys who make the parts, not those who sell them. And it's a praise, not than a criticism.

Re.: pinout: yes, I'm aware. From the pics above, you can see it's the exact same test rig I used.
Btw, the left section of my rig is for the 317; and the ones I have all test good, no worries on that front.
 
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There are over thirty thousand of them in stock at DigiKey Switzerland. But the guaranteed supply chain does impose extra costs; DigiKey Switzerland charges almost one full Euro per piece. At qty=10 the price drops to 0.81 Euros per piece.

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There are over thirty thousand of them in stock at DigiKey Switzerland. But the guaranteed supply chain does impose extra costs; DigiKey Switzerland charges almost one full Euro per piece. At qty=10 the price drops to 0.81 Euros per piece.

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Thx Mark.
I usually do my shopping at Mouser. But I do forget things, or change my mind after an order is placed, so Ali or eBay come in handy for small orders. like a few bucks, so the risk is contained.
The intent of this post is to make people aware of some possibly major issues since the faulty items come from 3 different vendors. One of these has been very upfront stating that "this is not a problem, we have sold a lot of these products, other customers can use it normally". I assume the "other customers" suffer in silence.
 
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I don’t want to pile on, but let this be a warning not to buy semiconductors from random sellers on eBay, Aliexpress, Amazon. At least nothing caught fire or was damaged on your circuit board.

Stick to distributors first, and to sellers that have been confirmed as reliable sources for the specific products they are selling. There are good sellers out there, but the other 98% are selling counterfeits and defective rejects.
 
Automotive parts aren’t made in dubious places either. Every single part of the supply chain has strict quality controls applied no matter where they’re made.
I beg to differ.
If I may step out of my own topic just for a bit.
It depends on which car. My experiences with 3 different VW, from new:
  • VW #1: door knob coming off, MTFB: 1 week
  • VW #2: coolant hose leaking, MTFB: 2 months
  • VW #3: auto transmission total failure, MTFB: 2 years + 1 month. Because it was fresh out of warranty, VW generously offered to take over half of the repair cost: 6K
Now I'm on my 2nd MB, so far so good.
 
I beg to differ.
If I may step out of my own topic just for a bit.
It depends on which car. My experiences with 3 different VW, from new:
  • VW #1: door knob coming off, MTFB: 1 week
  • VW #2: coolant hose leaking, MTFB: 2 months
  • VW #3: auto transmission total failure, MTFB: 2 years + 1 month. Because it was fresh out of warranty, VW generously offered to take over half of the repair cost: 6K
Now I'm on my 2nd MB, so far so good.
Remember that "Quality" often doesn't mean that nothing ever breaks, but it does mean that you know where your components come from and who made them - big difference.
 
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