Hi...
I bought two transistors MJ15024 and two MJ15025.
The MJ15025 is from OnSemi, and it appears to be OK...
The other is from "motorola", and their top just jumped out when I attached it in a plain heatsink
Look...
By the inside, can you tell me if it appears to be realy fake?
I bought two transistors MJ15024 and two MJ15025.
The MJ15025 is from OnSemi, and it appears to be OK...
The other is from "motorola", and their top just jumped out when I attached it in a plain heatsink
Look...
By the inside, can you tell me if it appears to be realy fake?
Attachments
Oi Fernando, como vai ?
Realiable dealers can be hard to find here in Brazil. I myself bought fake Toshiba power transistors at attractive prices here in my city. I didn't realize they were fakes until I started examining them really close before installation, read a lot of material on the Internet and took a look at its real price.
Try to source your critical components (power trans.) from realiable sources like Farnell ( www.farnel.com.br ). It is not cheap but it is guaranteed. I bought a pair of OnSemi's MJL3281/MJL1302 and they worked great ! Genuine pieces.
Abraços,
João Pedro
Realiable dealers can be hard to find here in Brazil. I myself bought fake Toshiba power transistors at attractive prices here in my city. I didn't realize they were fakes until I started examining them really close before installation, read a lot of material on the Internet and took a look at its real price.
Try to source your critical components (power trans.) from realiable sources like Farnell ( www.farnel.com.br ). It is not cheap but it is guaranteed. I bought a pair of OnSemi's MJL3281/MJL1302 and they worked great ! Genuine pieces.
Abraços,
João Pedro
-_nando-_ said:Hi...
I bought two transistors MJ15024 and two MJ15025.
The MJ15025 is from OnSemi, and it appears to be OK...
The other is from "motorola", and their top just jumped out when I attached it in a plain heatsink
Look...
By the inside, can you tell me if it appears to be realy fake?
Opa ! E aí João?
The bigger amount of fake parts is named "toshiba". I bought a lot of them, 2N3055, 3281... Pfff...
I took two pictures of my OnSemi's transistors... I'm not sure about them, maybe they're fake too...
They didn't opened like the "motorola", but It's not enough...
I payed 9 reais for each one, or 3,60 us dollars... NOT CHEAP too !
Should I open these others too?
Abraços !
The bigger amount of fake parts is named "toshiba". I bought a lot of them, 2N3055, 3281... Pfff...
I took two pictures of my OnSemi's transistors... I'm not sure about them, maybe they're fake too...
They didn't opened like the "motorola", but It's not enough...
I payed 9 reais for each one, or 3,60 us dollars... NOT CHEAP too !
Should I open these others too?
Abraços !
Attachments
Yes, they make fakes of OnSemi too 
I opened them. One apears to be genuine, with much more huge wires, and without any silicon grease. Much more harder to open than the fake one !
The other, is the same trash as the "motorola"... Thinny wires, much more easy to open (but this didn't open by itself hahah), and the silicon grease. I tryed to remove the grease to take a pic, but the die separated from the body (
) and I lost it. 
The first pic is of the genuine device. I don't know if it's genuine or a better fake...
I opened them. One apears to be genuine, with much more huge wires, and without any silicon grease. Much more harder to open than the fake one !
The other, is the same trash as the "motorola"... Thinny wires, much more easy to open (but this didn't open by itself hahah), and the silicon grease. I tryed to remove the grease to take a pic, but the die separated from the body (
) and I lost it. The first pic is of the genuine device. I don't know if it's genuine or a better fake...
Attachments
What REALLY hurts is when you are trying something new and put these things in. When the pop the first thought is to try to figure out what you did wrong. This wasted days of my time once checking and rechecking to figure out what I was doing wrong. When I found out is wan't me but the counterfieter I was (as in the Monty Python sketch) like Kierekegard sitting in the corner biting the heads off wickets!
This picture shows a genuine MJ1502x (the base bonding wire was accidentally broken while opening the case).
The one shown was a very old device (from late 80's) and currently manufactured ones are probably going to look slightly different, but note the size and fringed design of the die, the size and the tickness of the copper coin on which the die is mounted and the absence of any white silicone.
There are threads on fakes and fake identificacion on this forum, and some of them include interesting pictures. Use the search engine and you'll find out...
An externally hosted image should be here but it was not working when we last tested it.
The one shown was a very old device (from late 80's) and currently manufactured ones are probably going to look slightly different, but note the size and fringed design of the die, the size and the tickness of the copper coin on which the die is mounted and the absence of any white silicone.
There are threads on fakes and fake identificacion on this forum, and some of them include interesting pictures. Use the search engine and you'll find out...
Well, if it makes anyone feel any better, I'm gonna tell I'm not sure how interested ON management will be, but they may be interested enough to ask some questions. Are you willing to give them some answers???
In the ealier pics, I noticed the lid of one of these fakes. Was thart the traditional Motorola "BatWing" on the lid? They are very particular about that logo. If it is not perfect they clean them off and do it again! Of coarse I dont' think Moto makes any descretes anymore. That is where ON Semi came from
I'm not sure how interested ON management will be, but they may be interested enough to ask some questions. Are you willing to give them some answers???In the ealier pics, I noticed the lid of one of these fakes. Was thart the traditional Motorola "BatWing" on the lid? They are very particular about that logo. If it is not perfect they clean them off and do it again! Of coarse I dont' think Moto makes any descretes anymore. That is where ON Semi came from
Motorola havent made transistors in quite a while. The division of Motorola that did discrete parts became OnSemi.
Rod Elliot has good information on fake parts:
http://sound.westhost.com/counterfeit.htm
Rod Elliot has good information on fake parts:
http://sound.westhost.com/counterfeit.htm
So, all moto discrete transistors are fake? Huh ! Good to know... The most funny is that 80% of fakes are sold with moto or toshiba logo... hehehehe ! 
Yes, I'm feeling better heheh ! I can't imagine blow my amp because of these fakes transistors... Thank god I discoveried it first !
But anyway, not nice pay for a thing like this, and wasn't cheap !
OFF: Hum, if you want to see, take a look on my 3886's PCB, I finishied right now !
Yes, I'm feeling better heheh ! I can't imagine blow my amp because of these fakes transistors... Thank god I discoveried it first !
But anyway, not nice pay for a thing like this, and wasn't cheap !
OFF: Hum, if you want to see, take a look on my 3886's PCB, I finishied right now !
Oi Fernando !
Not really. Your dealer may have and old stock for certain parts. Of course it is much riskier to buy parts from companies that have extinguished or changed names. Also risky to buy parts that are not manufactured anymore (such as Toshiba's 2SA1302/2SC1943), you can find them, but probably they are fakes.
Again, my suggestion: pay more and buy from realiable sources. No pain, if something goes wrong you can almost be certain it is your fault (and not the transistor's) and you get maximum performance.
Abraços,
João Pedro
Not really. Your dealer may have and old stock for certain parts. Of course it is much riskier to buy parts from companies that have extinguished or changed names. Also risky to buy parts that are not manufactured anymore (such as Toshiba's 2SA1302/2SC1943), you can find them, but probably they are fakes.
Again, my suggestion: pay more and buy from realiable sources. No pain, if something goes wrong you can almost be certain it is your fault (and not the transistor's) and you get maximum performance.
Abraços,
João Pedro
-_nando-_ said:So, all moto discrete transistors are fake? Huh ! Good to know... The most funny is that 80% of fakes are sold with moto or toshiba logo... hehehehe !
Yes, I'm feeling better heheh ! I can't imagine blow my amp because of these fakes transistors... Thank god I discoveried it first !
But anyway, not nice pay for a thing like this, and wasn't cheap !
OFF: Hum, if you want to see, take a look on my 3886's PCB, I finishied right now !
Dear folks,
Photo of the inside of genuine (Onsemi sample) MJ15003:
http://sziget.mine.nu/~danko/aramkor/dscn7342.jpg
Regards,
Photo of the inside of genuine (Onsemi sample) MJ15003:
http://sziget.mine.nu/~danko/aramkor/dscn7342.jpg
Regards,
Part counterfeiting is a real problem, and not just for these manufacturers. Many of the fake parts are sold through brokers that specialize in obselete semiconductors.
I sold some ADC's on eBay a couple of years ago, and I received many e-mails asking if they were the genuine article. Let's hope that kind of activity does not appear on this forum.
I sold some ADC's on eBay a couple of years ago, and I received many e-mails asking if they were the genuine article. Let's hope that kind of activity does not appear on this forum.
I got some MJ21193/94's from AVnet (first tier ON distributor) last year. The 3's were MOT and the 4's were ON. Both were genuine, so basically just because someone has stock of the MOT's does not make them fake... use of common sense overrides this myth.
The pictures on the first post have font that clearly looks fake... good fakes can duplicate the silk screening well... this is clearly a bad one.... lol even fakes have levels.
The pictures on the first post have font that clearly looks fake... good fakes can duplicate the silk screening well... this is clearly a bad one.... lol even fakes have levels.
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