Could anyone tell me if these trannies are fake or not?😕
I bought this 2sa1407 several years ago from a reputable Sanyo dealer.
Then i bought this one right now from the same shop
2SC3601
Regards,
zsaudio
I bought this 2sa1407 several years ago from a reputable Sanyo dealer.
Then i bought this one right now from the same shop
2SC3601
Regards,
zsaudio
try some of these..
- case comparison with genuine parts
- open case to see its chip and its dimension (destructive)
- measurement of electrical parameters (max)
(for bjt : hfe, Vcemax, Icmax, Pmax, ...Ft)
- case comparison with genuine parts
- open case to see its chip and its dimension (destructive)
- measurement of electrical parameters (max)
(for bjt : hfe, Vcemax, Icmax, Pmax, ...Ft)
There is a company in the UK that offer parts and hard to find parts. They have a one year guarantee,parts are tested before sending. ISO Approved, and they deal with some big company's too,eg. Bosch, Intel ect. But they have a minimum order of 130 Euro. So no worries when buying from them. Can I post the name of the company here or is that against forum rules?
I think, you can post this name.
mean you this company?
Mil/Aerospace Division - Bipolar NPN
Magnatec. ALFET Lateral MOSFETs
or this:
Sanken Power Systems (UK) Ltd
Here I am with 2sj109bl
Have orderd them at little diode in england some times ago.
Now they have crazy prices for that part.
Thougt they where genuine.
Idss measured well beween 6,6mA at the lowest an 8,9mA at the highest.
But had 2 of the 4 at the frontend of an Aleph J and threre was hum.
Replaced them by a matched pair 2sj74 hum was gone.
Now i am not so sure anymore that they are genuine.
what do you think?
Have orderd them at little diode in england some times ago.
Now they have crazy prices for that part.
Thougt they where genuine.
Idss measured well beween 6,6mA at the lowest an 8,9mA at the highest.
But had 2 of the 4 at the frontend of an Aleph J and threre was hum.
Replaced them by a matched pair 2sj74 hum was gone.
Now i am not so sure anymore that they are genuine.
what do you think?
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They got the right looks and IDSS though. Don't know if hum in a certain build can tell directly, I guess you should try them in some other circuits too. John Curl style line stage test maybe.
Possible fakes from MCM?
Greetings,
I've been trying to repair a Denon DRA-600. I've gone through several sets of output transistors. I finally opened one up. This is supposedly a 2SA1106 purchased from MCM a few months ago. The die is only 1.3 mm on each side (1.74 square mm). I had the power supply current limited to about 300 mA (although there were some capacitors that could have dumped current) and this and its complement blew.
Do you think this is a fake?
Greetings,
I've been trying to repair a Denon DRA-600. I've gone through several sets of output transistors. I finally opened one up. This is supposedly a 2SA1106 purchased from MCM a few months ago. The die is only 1.3 mm on each side (1.74 square mm). I had the power supply current limited to about 300 mA (although there were some capacitors that could have dumped current) and this and its complement blew.
Do you think this is a fake?
Attachments
2SJ74BL
I got four 2SJ74BL jfets from an eBay HK seller that are very strange.
I tested them for Idss and with great surprise at only -6Vdc (the first battery at hand, a not fully charged 9V) it was over -100mA. I tried one at -9V and it exploded. Well, I think there's no doubt they are not 2SJ74BL, I'm going to ask refund.
I got four 2SJ74BL jfets from an eBay HK seller that are very strange.
I tested them for Idss and with great surprise at only -6Vdc (the first battery at hand, a not fully charged 9V) it was over -100mA. I tried one at -9V and it exploded. Well, I think there's no doubt they are not 2SJ74BL, I'm going to ask refund.
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m.massimo, your's J74 are fakes. Front surfaces are sanded down, they are too thin.
Originals should have glossy surface and different font type.
Originals should have glossy surface and different font type.
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Thank you for your comment. I've many original K170, but I didn't noted that difference. Good point. I've just taken some measures. K170 are 3.87mm, these fakes are 3.47mm, Toshiba states 4.1 as maximum.
There's no doubt that are fake with 100mA Idss at 6Vdc!
They sold about one hundred of them and nobody reported something strange.
I'm very surprised at it. Anybody tested them before inserting in a circuit?
I'm guessing that you forward-biased the G-S or G-D junction due to different pinout on the fakes. They could be re-marked j175 or similar p-channel switches, which are much cheaper.
You can try measuring Ciss across G-S with a smart SMD tester like the Mastech MS8910. All my original Toshiba 2sk170 are within / - 20 % of the published spec. The fakes tend to have very low values like 5 pF because of the smaller die area, but this is not conclusive. Some of the re-marks may be large-die devices.
The last semiconductor I purchased from MCM was a fake.
Their management is aware of the problem.
Their management is aware of the problem.
I'm adding a few photos of obvious fakes to this thread that I ended up with awhile ago for reference.
They all looked bad right out of the bag, and after some close inspection I found several with remains of the original markings. I went through my parts and just happened to have some of the original parts on hand for comparison. These were apparently sanded down.
Sloppy work by sloppy people.
They all looked bad right out of the bag, and after some close inspection I found several with remains of the original markings. I went through my parts and just happened to have some of the original parts on hand for comparison. These were apparently sanded down.
Sloppy work by sloppy people.
