fake transistors

[tinkerbell]

might just being paranoid, but i blew some of my output transistors and got a new set from www.futurlec.com

the old ones are motorola MJL21194 and the new ones are ONsemi ones

(i know onsemi took over motorola semis or something?)

problem is that they look different in a few ways:

the legs taper differently, the legs have stalks, the top of the rear metal has an indent (kinda)

below is the pic from Rod's site http://sound.westhost.com/counterfeit.htm



and attached is a pic of my new ones

i seached here and no one has reported fake MJL's (maybe too cheap to fake?) but i just thought i would ask???

[jaycee]

They dont look anything like the samples I recieved directly from OnSemi fairly recently... so beware.

[jackinnj]

I got these from Avnet -- MJL21194 -- f you order from On-Semi's webstore the orders are filled by Avnet (but Avnet is not the lowest priced vendor) -- and you usually have to order a few hundred from them :

[MikeB]

Yes, i follow jaycee, i also got some samples recently, the look like
the pictures from Rod and jackinnj !
It's very sure you don't have onsemi-devices, but does not mean
they are bad...

Did you really pay 2,90$ ? Futurelec don't sell them as onsemi, so
you can't pee at their legs... Onsemi lists them for 2,90$, can't
imagaine that any reseller sells them at this price...

Mike

[BrianDonegan]

Well, they don't sell them as On, but they sell non-On devices marked as On. Just as bad in my book.

On a related note, I see the B&D Enterprises is trying to provide a fake transistor eveluation program. Last I checked only one device tested so far. http://www.bdent.com/nesda.jsp

[hienrich]

those pictures tells who they are!

I got originals too but does not look like on the attached.

so beware.

[tinkerbell]

yes, i paid $2.90us = $3.80aud (compared to $11.95aud at Jaycar)

i saw various other sites advertising them at $3.50 and $3.80 etc and i thought that $2.90 was just the cheapest of them all...

well, thanks for confirming my suspicion.

but as one poster said - they may not be true on-semi's but they might do the same job?

i will contact futurlec and confirm that this is the case, then i will install them and run them and if they blow - i have a 90 day guarentte...

(it is lucky i only blew one channels, i have a working set of Motorola's in the other side for direct comparison of output performance )

[BrianDonegan]

If you have a diode test function on your DMM you could compare the pin readings to the known good ones. That would give you at least some idea. Be careful not to blow any other devices when they fakes blow...

[Zero Cool]

I found this test circuit diagram i have been using to spot fake transistors. I havent found any fake ones yet, but i usually by from reputable sources.

Zc
P.S. thank you to whom ever designed this test circuit.

[jakobsladderz]

These are the same as some fakes I recently returned, purchased from an australian wholesaler/retailer. They were motorola labelled (M in circle), date code CX002 something meaning 2000. I sent images very similar to yours to ON-Semi tech advice and got a reply indicating that the Motorola had got out of semi manufacture in '98 so they could not possibly have been theirs. Also, the packaging was not theirs. I also noticed that the mounting was not flat (hold two together by the bolt holes and there's a good 1/2mm gap. Mine were 21193's but apparently the 21194's were also similar packaged and definately counterfeit.
If yours are on-semi labelled maybe they have got a little cleverer but the packaging is the same (legs taper to the middle of the package not the middle of each leg, bumps in the plastic where each leg comes out, slightly thinner) and does not match the ON-semi or motorola datasheet package design, so they are definately counterfeit parts.
Return them to the supplier and inform them of what you have found. PM me if you would like photos of the ones I have returned.