I agree with richie00boy, the left looks fake.
Audio Lab GA have already been caught selling fake Sankens, so it wouldn't be a big surprise if they're selling fake Toshiba's too.
See this thread:
http://www.diyaudio.com/forums/showthread.php?postid=868812#post868812
Audio Lab GA have already been caught selling fake Sankens, so it wouldn't be a big surprise if they're selling fake Toshiba's too.
See this thread:
http://www.diyaudio.com/forums/showthread.php?postid=868812#post868812
Given their being used for output trannies I don’t think I'm going to risk it. It’s a good thing I only purchased the devices shown so I’m out about $11 bucks so it could have been worse. I think I will get some from someplace else. I might go with a replacement from On semiconductor that’s still an active device in order to reduce the chance of getting junk.
Hi There,
Check their BE capacitance against the originals. Legit devices should have similar capacitance suggesting the same size die and similar semiconductor topology. Fakes I've seen use smaller die and their junction capacitance is lower. Just a quick-and-dirty test without a curve tracer.
Paul
Check their BE capacitance against the originals. Legit devices should have similar capacitance suggesting the same size die and similar semiconductor topology. Fakes I've seen use smaller die and their junction capacitance is lower. Just a quick-and-dirty test without a curve tracer.
Paul
Hi Paul,
Yes. If you check earlier in this thread you should find some measured capacitance values and more pictures. It is a very long thread.
-Chris
Yes. If you check earlier in this thread you should find some measured capacitance values and more pictures. It is a very long thread.
-Chris
I'd say there all fake, the ones MikeB posted look real. I always seem to see the fake ones with the wrong style of "o", they use either "O", "O with angled slash", but the originals from toshiba have the "O with slash down the middle".
The 2sc one isn't even from the same place as the 2sa, look at the small black area around the hole. I've even seen the hole not sentered with the black part(or green).
Just what I've seen latley.
BTW guru's, how do you open them?
The 2sc one isn't even from the same place as the 2sa, look at the small black area around the hole. I've even seen the hole not sentered with the black part(or green).
Just what I've seen latley.
BTW guru's, how do you open them?
The Motorola branded MJL21194 is *definitely fake*. These have never been made with the Motorola logo as by the time this transistor was introduced, OnSemi had taken over.
The MJL21193 looks real, I just compared it to one I have sitting around.
As I said in an earlier post - AudioLab GA have been caught KNOWINGLY selling fake transistors before. My advice would be to return them, demand your money back, and either source them from OnSemi as samples, or from Digi-Key/Mouser.
The MJL21193 looks real, I just compared it to one I have sitting around.
As I said in an earlier post - AudioLab GA have been caught KNOWINGLY selling fake transistors before. My advice would be to return them, demand your money back, and either source them from OnSemi as samples, or from Digi-Key/Mouser.
Yes, you are showing a lot of fake units
But related to put them over a flat surface, well, i am finding almost all them bad doing this kind of measurements.
I use to sand all them using number 500 sandpaper, as they are, almost all, not perfect surface contacts, and you will see depressions and small bubbles over the chromium finish, and also small differences between the plastic case and the metal casing.
The difference obtained after sanding, using a thermal compound and not using insulation is enormous....as if you perceive some heat in the top of case, when transistor is operating, the dissipation is not adequated...this finger-o-meter works fine, but do not work with radio frequency units with power on, as the heat you will perceive will be radio frequency...not the normal substances heating.
I use to insulate the heatsinks from the enclosure, and also the PNP heatsing insulated related the NPN heatsink.
Check your transistors using a very small quantity of white silicon thermal compound and after press them against a flat glass surface..... you will see, observing the metal surface what parts had mechanical contact and the parts that have not good contact.
Give a kiss into the flat units you have..... those flat ones are very difficult to find...less than 5 percent of the ones i found.
Test them before use screws..... some of them bend after beeing screwed into the heatsink...because the holes distance not completelly adequated or because of the already curved heatsink surface...test must be made with new units.
You will see that many transistors are rounded downwards, and that an enormous bubble of air will exist, unless you filled that space with thermal compound.
Sorry the english...not so good.
regards,
Carlos
But related to put them over a flat surface, well, i am finding almost all them bad doing this kind of measurements.
I use to sand all them using number 500 sandpaper, as they are, almost all, not perfect surface contacts, and you will see depressions and small bubbles over the chromium finish, and also small differences between the plastic case and the metal casing.
The difference obtained after sanding, using a thermal compound and not using insulation is enormous....as if you perceive some heat in the top of case, when transistor is operating, the dissipation is not adequated...this finger-o-meter works fine, but do not work with radio frequency units with power on, as the heat you will perceive will be radio frequency...not the normal substances heating.
I use to insulate the heatsinks from the enclosure, and also the PNP heatsing insulated related the NPN heatsink.
Check your transistors using a very small quantity of white silicon thermal compound and after press them against a flat glass surface..... you will see, observing the metal surface what parts had mechanical contact and the parts that have not good contact.
Give a kiss into the flat units you have..... those flat ones are very difficult to find...less than 5 percent of the ones i found.
Test them before use screws..... some of them bend after beeing screwed into the heatsink...because the holes distance not completelly adequated or because of the already curved heatsink surface...test must be made with new units.
You will see that many transistors are rounded downwards, and that an enormous bubble of air will exist, unless you filled that space with thermal compound.
Sorry the english...not so good.
regards,
Carlos
I have bought 1 BD317 and 1 BD318 by "ST". I seached on their site but did not find any of these two! I guess that thees are fakes! Another prof for it is that on BD317 there is no logo at all! All that there is is just BD317 and SH0452!! 
On the other is printed BD318 and SH0518!
I'm shure that these are fakes and probably inside they are just regular 2N3055
On the other is printed BD318 and SH0518!
I'm shure that these are fakes and probably inside they are just regular 2N3055
According to On Semi themselves, the date code on the device means it's a fake. To quote Rod's site
"This device does not match our packaging and marking specifications. It is not ON Semi's or Motorola's device, because there is the year of production: 2000. ON Semi had take over the portfolio from Motorola in 1998. Also Motorola is not producing any semiconductors from this date, only whole electrical appliances."
The date code suggests manufacture in 2000.
"This device does not match our packaging and marking specifications. It is not ON Semi's or Motorola's device, because there is the year of production: 2000. ON Semi had take over the portfolio from Motorola in 1998. Also Motorola is not producing any semiconductors from this date, only whole electrical appliances."
The date code suggests manufacture in 2000.
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