Fake and real components

[Gaber Mohamed Boraey]

Hello everyone

I’m working daily on repair electronic boards, mainly UPS machines within different capacities

Most of the problems I see , is blown mosfet, Or IGBT or high voltage doide
When I purchase from local market, the complements for replace, sometimes they are fake, like few weeks ago, I’ve checked mosfet jcs3205 and when I test before install, it gives strange readings, although it’s new and never soldered before

One time before also, over install mosfets and the machine worked fine and everything ok, but when there a load these replaced components damage again, and only solved this by replacing different components from similar board, “ not from supplier but from trusted stock “

Is there any way to check if the components fake or real?, have you met anything like this while you’re repairing electronics?

Please lemme know

 

[betwixt]

Fakes may look identical to the real devices, the only way to be sure is to purchase from an accredited supplier. Check the manufacturers web site, they often list their distributors and will provide a certificate of conformity (traceability to source) with an order.

Brian.

 

[KlausST]

Hi,

I can only agree with Brian: Buy from a reliable source.

You wrote about the (fake) MOSFET you bought.
Mosfets could easily get destroyed by ESD .. during storage, packaging handling, shipping....
No need to get soldered ... to become destroyed. So it still might have been an original one.

ESD damage can not be checked visually. Even electrical checks are not reliable, ofthen just show increased leakage currents.
ESD even may cause long term failure. (so you don´t see any failure at the time you solder them in)

Klaus

 

[Gaber Mohamed Boraey]

Thanks for reply

How you think of this method of testing?, I think it can be good way for test and be sure of the component used, if fake or original it’s for mosfets

I think for transistor and IGBT can be somehow like this comparing test with data sheet readings and applying load on the part

Please look and let me know how you think

 

[barry]

Thanks for reply

How you think of this method of testing?, I think it can be good way for test and be sure of the component used, if fake or original it’s for mosfets

I think for transistor and IGBT can be somehow like this comparing test with data sheet readings and applying load on the part

Please look and let me know how you think

There's no test that will tell if a part is fake or not. A fake part could very well measure the same as an authentic one.

 

[Gaber Mohamed Boraey]

There's no test that will tell if a part is fake or not. A fake part could very well measure the same as an authentic one.

Maybe, have you watched the video?

 

[aliarifat794]

Hello everyone

I’m working daily on repair electronic boards, mainly UPS machines within different capacities

Most of the problems I see , is blown mosfet, Or IGBT or high voltage doide
When I purchase from local market, the complements for replace, sometimes they are fake, like few weeks ago, I’ve checked mosfet jcs3205 and when I test before install, it gives strange readings, although it’s new and never soldered before

One time before also, over install mosfets and the machine worked fine and everything ok, but when there a load these replaced components damage again, and only solved this by replacing different components from similar board, “ not from supplier but from trusted stock “

Is there any way to check if the components fake or real?, have you met anything like this while you’re repairing electronics?

Please lemme know

One way is to use a ready-made component tester. Another way can be looking at a particular component's datasheet and trying an application circuit mentioned there.

 

[barry]

Maybe, have you watched the video?

Again: Just because the measured parameters meet the data sheet values, it doesn't mean the component is authentic. All you've proved is that the part meets the specifications, nothing more can be inferred.

Just because my photograph of the Mona Lisa is very high resolution doesn't mean it IS the Mona Lisa.

 

[Gaber Mohamed Boraey]

Again: Just because the measured parameters meet the data sheet values, it doesn't mean the component is authentic. All you've proved is that the part meets the specifications, nothing more can be inferred.

Just because my photograph of the Mona Lisa is very high resolution doesn't mean it IS the Mona Lisa.

Okay, thanks

--- Updated Jun 27, 2024 ---

One way is to use a ready-made component tester. Another way can be looking at a particular component's datasheet and trying an application circuit mentioned there.

Like what tester sir you think it can detect if the component fake or real?, can you send a link?

 

[dick_freebird]

There's a rainbow of fakery out there. From test floor rejects ("real" but not right) to up-branding or cross-branding lower grade or third party "equivalent" parts to be what was asked for.

You might get any of those to pass the limited datasheet electrical tables but that cannot tell you which fab line, which mask revs (I see many standard linears with Rev E masks and disconnected devices, somebody tried something), are your parts the current production version or something they walked away from years back? L

 

[Gaber Mohamed Boraey]

are your parts the current production version or something they walked away from years back? L

How can I know that?

 

[BradtheRad]

It helps to consult old electronics catalogs to see what devices were on the market years ago. Many devices are obsolete now and replaced with surface-mount packages, or faster versions, etc.

Sellers may advertise components as NOS (new old stock), in original package, never used. (Ebay has lots of these listings.) A few individuals sell privately. Maybe, just maybe, if a seller has overwhelming positive feedback, you can trust the merchandise.

Some of us remember when hobbyists were catered to (Heathkit, Lafayette, Radio Shack, mail order electronics houses). This declined as devices became miniaturized, faster (in the GHz), with reduced fixability and greater 'throw-awayability'. Simultaneously fake components grew numerous, making things harder for hobbyists and manufacturers alike.

 

[betwixt]

The difference between fake and real isn't necessarily the measurable electrical characteristics, its how well the part was manufactured and tested. A genuine source would have good quality control and regular sample testing to push components to their limits to make sure they exceeded specification. A fake manufacturer would do a 'go / no go' check and ship it.

Although reputable manufacturers are careful to destroy bad batches, they do sometimes slip out or get stolen and distributed. They ARE the genuine part but failed batch quality test so some may work perfectly and some not. The manufacturer can't test every part to destruction or they would have nothing left to sell so they rely on sampling say one in every hundred to confirm specifications are met. One fail means the whole batch is suspect and should be rejected but it could be that the other 99 are fine. Regardless, it would be disreputable of the manufacturer to release a suspect batch so they try to stop them all going to market.

The only way to be sure is to see traceability back to manufacturer, that's why semiconductors have batch code or date code numbers on them and reputable sellers can give you a paper trail back to source. Check the seller has ISO9001 certification to confirm their standards are verified.

Brian.