Man I'm soo sick of fake transtors

[diydidi]

If your'e like me and fed up with all this BS fake transistors out there, lets talk about it. Post your pics, give some advice, name those sellers, share reputable sellers. Cmon...

[nickb]

If your'e like me and fed up with all this BS fake transistors out there, lets talk about it. Post your pics, give some advice, name those sellers, share reputable sellers. Cmon...

Can't help much with where you are but I only buy semiconductors from Mouser, Digikey and Jameco in order of preference. I never had a problem.

I did make an exception with some obsolete PNP RF TO5 transistors on the grey market.. so far they are still working.

[Jazz P Bass]

I could not believe it but I got some fake ones from MCM.
I popped them open after they failed & sure enough.
Fake.
I called them up & they put me through to a sales engineer & he said he would research it.
Got an email back i week later & he agreed.
They have since removed them from there inventory.

[diydidi]

I could not believe it but I got some fake ones from MCM.
I popped them open after they failed & sure enough.
Fake.
I called them up & they put me through to a sales engineer & he said he would research it.
Got an email back i week later & he agreed.
They have since removed them from there inventory.

So what do you look for when you pop them open? Obviously that small die with the white glue. AARGH.. What else?

[bob p]

I prefer to only buy from the big distributors like Newark, Allied, Mouser, Digikey. They go on the record that everything that they sell is 100% original, with provenance. I haven't had any bad luck yet, knock on wood.

Some people try to buy NOS transistors, but the counterfeiters are even faking old power transistors c.1970. On ebay you'll see the fakes are all too common.

What really amazed me is the demand for genuine old-stock transistors that are pulled from working gear. I recently pulled all of the original output transistors out of a working Phase Linear amp to replace them with new production ON Semi products that have a significantly improved SOA. I placed three different batches of working pull transistors on ebay, and much to my surprise every lot sold out by Buy-It-Now within 30 minutes of the auction's start. Someone out there is definitely looking for these things.

Here are some ebay pictures. If you look closely, you can tell originals from fakes by the case design. Very often you'll find sharply cylindrical cases instead rounded cases, different fonts, different colored insulators on the back, and a different case backing.

FAKE:




REAL:

[Jazz P Bass]

How much more effort would it take to make them correctly?

[Steve Conner]

I just bought a couple of 400 amp IGBT modules on EBay, only to discover they were cheaper 300 amp ones remarked with the part number of a more expensive device. The tiny sandpaper scratches gave it away, and the barcode on the device (which the counterfeiter hadn't thought to change) revealed the real part number.

[Enzo]

All those stories and more are why I never even consider buying parts on ebay.

How much more effort would it take to make them correctly?

A ton. These are counterfeiters, all they care about is selling the part. They don't even really care if it works AT ALL. To make it right means you have to fabricate the actual transistor innards, and make up the part correctly. If you take any old reject transistor dies and stick them into cases, voila, you have transistors. Stick the same innards into every part you make. Label them for whatever you want. Sell them and run.

I'd say the amount of added effort would be about like the difference between engraving convincing counterfeit $100 bills and printing a bunch versus cutting up stacks of newspaper with a real bill on the top. Both look the same in a brief case.

[frus]

He probably meant, to make them correctly in appearance, so that they can fool us easier

[diydidi]

Just last week I had to chuck about 400 transistors. All bought from Indian/ chinese vendors here in South Africa. Why is it that most of these fakes are copies of The great "amplifier" transistors. And it seems to me that only large package (T-03, T-03P, T247, type packages) are being faked and not the To-92, to-220 packages? I might be wrong.

[Enzo]

Just an opinion, but people look up a power transistor in a TO3 and find price tags of $4 and up. It makes more sense for a criminal to fake those than to fake small parts that sell for 8 cents apiece.

[bob p]

Jesse James robbed banks because that's where they kept the money.

$4 to $5 is about the price that you have to pay for new TO-3 from any of the big distributors. There's big profit in counterfeiting high priced items like TO-3. Even if you buy them by the tray from the manufacturer they're going to cost $2 each.

I have a HiFi amp that had 1 pair of bad transistors out of 8 pair. Because I wanted to keep a matched set, instead of searching for 2 matching replacements, I just bought a matched set of 16 new transistors. The new transistors had a significantly better SOA, so I wasn't at all reluctant to upgrade. What amazed me was that some guy was eager to pay $5 for every old transistor I was willing to offer. The idea of a free upgrade to transistors that have double the SOA makes me want to swap out the semis on my entire collection of amps.

[km6xz]

I never thought it would attract counterfeiters because transistors are so cheap. In the last 6 months however I got bit twice, once buying 12 power mosfets from a local full line parts wholesale business and the other was trying to find some RF power transistors, 2sc1969. I found only 1 in Russia so ordered from a source in China I have had good luck with(mostly because they have everything and ship all the way from China or $7 compared to $75 from Digikey) and I put 2 in a project I was working on they have very low output.I tested them on the curve tracer and they looked fine. So I made a test jig to run them are 30 MHz and found they were not RF transistors at all, just remarked common GP TO-220 npn transistors. I do not know the exact part but they test fine as a TIP31 which go for $0.37 versus a 2SC1969 which goes for $15.00 each.

[Steve Conner]

I think they concentrate on "the great amp transistors" because these are commonly bought for repair and DIY purposes by small tech shops and hobbyists who will be fooled easier than, say, Dell would by a batch of fake RAM chips.

A similar argument applies to the IGBT modules. Obviously the makers of the equipment they go in wouldn't be shopping for them on EBay, but they do blow up now and again, and you have maintenance managers at factories looking for replacements so they can get their older motor drives and induction furnaces going again.

[diydidi]

From now on Im taking a vice grip along to the shop. Pay for a sample and crack it open right there and then.