What do you think of the other parts, they LOOK okay to me but I've not
looked over many Toshiba parts. Obviously, beta test and Vce breakdown
will shed some light on them.
Hi Pete,
Truthfully, I would have to see the printing on the cases to say any more. Don't unseal the bag, you want it to be clear you haven't had direct access to the parts.
They should apologize and send you a full refund without having you ship the parts back. It was extremely clear to me that they knew full well they were selling you pulls. If they demand that you destroy them with proof, set a camera on record and pop the bag into the microwave. 10 sec ought to do it, and you get a cool light show.
-Chris
Truthfully, I would have to see the printing on the cases to say any more. Don't unseal the bag, you want it to be clear you haven't had direct access to the parts.
They should apologize and send you a full refund without having you ship the parts back. It was extremely clear to me that they knew full well they were selling you pulls. If they demand that you destroy them with proof, set a camera on record and pop the bag into the microwave. 10 sec ought to do it, and you get a cool light show.
-Chris
The company selling these has been in business since 1977 and sounds like a small
operation. I called them and no questions asked they agreed to refund the cost for
the 3 dual transistors and apologized for the error. He explained that the parts have
been hard to get and sometimes the sources are iffy. He said keep the parts.
I bought some LT1083 regulators in TO-3P package from jk_parts and wiped the markings on one with acetone last night which completely erased the printing. A real LT1083 I bought from Digi-Key some time back was unfazed by the acetone.
Most parts are indelibly marked by laser etching, aren't they? Might this be a quick way to check for fakes?
Most parts are indelibly marked by laser etching, aren't they? Might this be a quick way to check for fakes?
Not necessarily! I have plenty of devices marked with just paint or ink purchased in the days before fakes. And etches are commonly used by fakers when they do enough ... so no it's not a good way to check for fakes.
The only way to tell for sure "real or fake" is to test them in a rig where a piece of a equipment won't get damaged.
The only way to tell for sure "real or fake" is to test them in a rig where a piece of a equipment won't get damaged.
Hi PH104,
You can also check the markings against what the manufacturer specifies. One place where they often trip up is date codes.
I have several laser etched fakes here. The picture showed a real device and what was delivered was obviously fake. They measure really poorly against the beta spec for these parts too. I have yet to figure out the motivation for this because the cost has to be very similar.
-Chris
You can also check the markings against what the manufacturer specifies. One place where they often trip up is date codes.
I have several laser etched fakes here. The picture showed a real device and what was delivered was obviously fake. They measure really poorly against the beta spec for these parts too. I have yet to figure out the motivation for this because the cost has to be very similar.
-Chris
Thanks Anatech. These were pretty obvious fakes in other ways too. The Linear logo was even botched. Thanks for the date code tip. I also just noticed that the fake ones don't have the ejector marks on the case that LT shows in their specs.
I have some BB PCM1702K's off eBay that look legit in all respects but I don't know how to test them. I'd welcome suggestions if anyone knows how to do that simply.
Thanks
Phil
I have some BB PCM1702K's off eBay that look legit in all respects but I don't know how to test them. I'd welcome suggestions if anyone knows how to do that simply.
Thanks
Phil
Detection of fakes is a real pain ... as this thread shows with 94 pages so far! One of the other problems is "legit fakes". There are manufacturers who sell slightly off spec product at a discount instead of doing what they actually SHOULD do with them and destroy them. Every penny counts! So, fakers buy these up and label them. For a good many applications they are quite usable as labelled. For some, unfortunately, they aren't. Often these are labelled as made by the correct maker (after all, the die was made by them!) but poorly labelled.
It's such a jungle out there.
It's such a jungle out there.
Hi sbrook,
I don't know of any manufacturer who doesn't destroy off-spec parts. They can be subject to theft, but that is a criminal matter. A reputation to a foundry and fab is so important that they will not risk mislabeling defective product. Most off-spec products are discarded from the line into protected containers and have security all the way to destruction. It's a big problem and they do not want to end up on the list of non-compliant manufacturers. That'll shut down a foundry quick as can be.
-Chris
I don't know of any manufacturer who doesn't destroy off-spec parts. They can be subject to theft, but that is a criminal matter. A reputation to a foundry and fab is so important that they will not risk mislabeling defective product. Most off-spec products are discarded from the line into protected containers and have security all the way to destruction. It's a big problem and they do not want to end up on the list of non-compliant manufacturers. That'll shut down a foundry quick as can be.
-Chris
Hi Phil,
If in doubt, send them up here and I'll use them.They are one of my favorite D/A converters.
Hi Chris-
Hah! They're for my old Cal Audio CL-15 which I modified a bit several years ago. I'm considering around of mods after finishing up some other stuff. But it's a multi-layer board and a pain to work on. I'll let you know if I end up with useable pulls if you're interested.
But thanks again!
Phil
Interesting question, and one I may shed some light on.
When I started working in the electronics manufacturing industry in the early 2000s, it was in the transition phase when the manufacturers were switching from printing to laser etching. It took a while, but it seems all of them have abandoned printing, with the notable exception of Linear Technology.
In July last year, I reported in this very thread of encountering suspect TO-3P voltage regulators from the LT1083/1084/1085 family.
What I completely forgot to do was to post the promised pictures, so without further ado, here they are:
First a known genuine, brand new item for reference. The closeup is of the leads as that's where the best clues were in our case.
Please first read my post from July 2017 (if you haven't already) before continuing.
The one below is one of the worst examples in the batch I found, but to the naked eye, some others looked as good as the genuine items.
To determine if they were counterfeits or refurbished components, we had a look at them in the X-ray machine.
This is a genuine and a counterfeit side by side. Without me telling you, you should be able to see which one is the counterfeit.
Based on the fact that the internals are identical (apart from normal production variations), we took the conclusion that these are probably salvaged genuine parts with new leads grafted on and sold on as new items.
It has been confirmed that these parts did come from a broker, and not from an authorized reseller.
TO-3 and TO-3P packages are obsolete, and have been for a while.
As I still have access to a genuine and a counterfeit part, I will try the acetone test and see if that does the same to the printing as it did with your's.
Over on the EEVblog forum I posted the same results and asked why a seemingly mundane part as a voltage regulator was interesting enough to be counterfeited. A Chinese member responded that in Chinese DIY audiophile circles, these regulators have a bit of a mythical status, and that gives it high value.
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Hi jitter,
That is fascinating! I have to ask. Is it cheaper to obtain pulls, clean them up and reattach leads to them than it is to simply sell the real deal that is new? I can't believe there is money in this.
Thank you very much for posting the x-ray of those two parts. It's interesting stuff.
-Chris
That is fascinating! I have to ask. Is it cheaper to obtain pulls, clean them up and reattach leads to them than it is to simply sell the real deal that is new? I can't believe there is money in this.
Thank you very much for posting the x-ray of those two parts. It's interesting stuff.
-Chris