Toshiba 2SC3281/2SA1302 - Are these fakes?

[Phostenix]

Looks like the important pics didn't post. Here they are.

[ostripper]

OMG , those dies are small . ON semi NJW0281/0302 are 4 X larger ,the NJW21193/4's are 6 of those. FAKES !!!

mje15032/3 dies are the same size (drivers )
OS

edit - here is the real thing (big die - not glued on , either - attachment)

[Phostenix]

Thanks for the info on the driver transistors. I figured they were re-labeled. No sign of the faces being sanded that I could see, though. The cases are pretty shoddy on the 1302s. Lots of voids around the collector. All the scratches on the collectors looked suspicious to me, too. I didn't take any side shots, but they were all flat & straight.

BTW, thanks to everyone here that contributed earlier to the fakes threads. I found this doing research on something else & it has saved me from installing these junkers in an amp. Info here also helped me find the replacement numbers so that I could get them from Mouser. Thanks again!

[PMA]

2SA1302 fake:

[unclejed613]

here's the marking layout from a 2SA1943 datasheet. if you compare this with pictures of KNOWN ORIGINAL devices earlier in this thread, you will see the proper placement of the beta code as well. according to Toshiba's Semiconductor Reliability Handbook, the date code is a digit and letter, the digit being the last digit of the year, and the letter (A-L) is the month code (A for JAN, B for FEB, etc,.. with L for DEC). the dot is a factory code, and i've always seen a single dot here on all Toshiba power transistors. the other options are 2 dots or no dots. now for RoHS devices, the date code is underlined,

[mbongeni zulu]

i have almost the same problems with this transistors,5200 toshiba one of my amp module aclone amplyfire md800 was damaged,ireplaced them with pnps and it played well 10min, i raized a volume high not even 2 min fuses blown now i took from other channel all pnps npns 5 and 5.put volume full no problem now the other chanell as soon i raise a volume full it blown the problem now is they look the same toshiba how to identify i am in south africa.

[gaborbela]

Originally Posted by CrazzyAbtTubes

Oooooooo, this is interesting, one chip is smaller than the other, and there is some white stuff on the small one! That ain't a 100 Watt BJT!!!!!

The other one appears to have some copper pad, and has a much larger piece of silicon on it, I killed it!

Well that solves that mistery, I think when I need to find new Toshiba outputs.... I will just go to Ebay and buy some cheap SS amp such as the Fisher CA860 that the really good "O" types were found in.

Hello
I read over these thread because I have some so called original Toshiba transistors. Need for P3A project..
I purchased here in Toronto from local store "they told 100% orig".
So I break up one after I saw some picture here and sadly realized that 100% fake.
The number on the chip perfect (now is magnified many times so it does not look like) and engraved but the chip inside much smaller than the regular Toshiba's.
When the case similar to to the ON semi "has that island for the writing" that 100% fake after my experience.
Also when the chip is green but the lettering is black that 100% fake to.
That is the world we live even over the $5 + tax chip is fake.
And the store do not take (no exchange or refund) back sold semis!!!

Greetings Gabor

[ashok]

Can you measure base collector capacitance ?
That should be a dead give away.....isn't it ? Most DMM's nowadays seem to have some capability to measure capacitance.
Small wafers should have much lower capacitance. Check what the data sheet says about capacitance. Of course it will not be the same as you will have hardly any voltage on the terminals when you measure but the 'range' might be an indication.

I deliberately bought a fake 2sc5200 ( from Singapore...long ago !) to see what it was like. Must search it out and measure the capacitance.

[Jay]

Hi Gabor please remember that there is still possibility that a fake part may sound good.

A transistor has many characteristics. Some characteristics are relevant with sound, some are not. When a fake part needs to conform with power handling characteristics of the original, then they might sacrifice other characteristics more related to sound quality.

We don't know which characteristics are closer or farther than the original, but I think power handling (Vce max) is the critical characteristics, but fortunately it has no direct relevance with good sound.

Many low Vce transistors are good sounding, not so with high Vce ones.

I have found that in my country it is very hard to find original parts. Sankens (ring emitter) can handle high Vce (which is crucial for PA amplifiers to get the mega watt) but nothing can beat a Toshiba 2SC5200 ($2.7 a pair). Even the original Blue-Black 30M devices cannot "beat" them in my subjective listening test with many circuits.

My point is, if you don't need the high Vce rating, just listen to the transistor. Who knows it sound more preferable...

[Ian Finch]

Jay, the issue is that the buyer is being duped. False advertising and fraudulent business practice are in there too. The transistors could well squeak and whistle like a soprano and turn a piano into a glockenspiel but they are not what you bargained for.

Imagine your disappointment when you buy more of these wonderful fakes only to find they sound more like fog horns next time instead! Very few fakes come with any promise of pleasant distortion effects - most seem to sound awful, which shouldn't be surprising.
If you pay good money, you can expect good parts or the whole concept of global commercial trade becomes a nonsense of deception and theft. We would simply stop buying.

Then there really is the matter of power handling. If a pair of driver chips were indeed big enough to drive my 90W amplifier, why would I use anything more expensive than a driver transistor in the first place?