Thanks for the reply. I had nothing to loose so I cracked open one of each. See attached. The die size is 2mm x 2mm. I have never seen inside one of these but it looks a bit off, one isn't even centred properly.
God, its so hard to find anything in Australia and the postage is a killer from Mouser etc for just a couple of components. Maybe I am best to try and hunt down a pair of original 2SA1104/2SC2579 ? Sigh. Anyone got a couple lying around
Richard
God, its so hard to find anything in Australia and the postage is a killer from Mouser etc for just a couple of components. Maybe I am best to try and hunt down a pair of original 2SA1104/2SC2579 ? Sigh. Anyone got a couple lying around
Richard
Attachments
The chip of the original must be at least 5x5 mm. I disassembled an original one some time ago. The chip was much bigger than yours (about 5x5mm) and well centered. In Australia I don't know any seller nor here in Italy. I know that the transport costs are very high ... you pay much more for shipping than the cost of the transistor ..... But at least play it safe!
Current production genuine Toshiba TTA1943 and TTC5200 are also in stock at Electronic Components Distributor | JLCPCB & EasyEDA Parts Online store - LCSC.COM
Just looking at these now
, thanksIs it best to have the same transistors on both channels ? One channel is working fine.
The TTA/TTC version has a slightly smaller die, but supposedly equivalent power capacity to the original 2SC/2SA version. The “N” version is the original die size in a smaller cheaper to produce case. Either way would run the internal temperature a bit high compared to the original, but probably work in practice. A whole lot better than those fakes did.
What I would do would depend on how hot the circuit is running them (translation- why did they fail in the first place). If they are being run on the edge of capability, I might be inclined to switch over to MJL3281/1302 (ON semi) which would handle anything you could throw at original C5200 series or C3281’s. They have a BIGGER die than even the original C3281 Toshiba types. If they are being run at a sane power level, say under +/-45 volt supplies, the newer cheaper versions of the C5200 are fine. That is, if they are real Toshibas. There is also the Fairchild version of the C5200, and you can get those in the larger TO-264 case too. Still have to pay Mouser shipping prices, but better than having the amp blow up. And ANY of these are subject to availability these days - the product shortages might determine which way you have to go.
What I would do would depend on how hot the circuit is running them (translation- why did they fail in the first place). If they are being run on the edge of capability, I might be inclined to switch over to MJL3281/1302 (ON semi) which would handle anything you could throw at original C5200 series or C3281’s. They have a BIGGER die than even the original C3281 Toshiba types. If they are being run at a sane power level, say under +/-45 volt supplies, the newer cheaper versions of the C5200 are fine. That is, if they are real Toshibas. There is also the Fairchild version of the C5200, and you can get those in the larger TO-264 case too. Still have to pay Mouser shipping prices, but better than having the amp blow up. And ANY of these are subject to availability these days - the product shortages might determine which way you have to go.
As long as they are NOT darlingtons they would be suitable. The LAPT types would be an upgrade, but they also make run of the mill triple diffused types. Those would be pretty much equivalent to the C5200’s. Consult the data sheets to see which any particular types are. They change and go obsolete often enough nowadays that it’s hard to keep track of which is which.
They are LAPT and I bought a tube because I fear they will go out of production. They might be one of the nicer transistor pairs still purchasable (true genuine from authorized distributors.) 160W.
The 2SC6145 is an NPN transistor of 230 V, 15 A. The product has constant hFE characteristics in a wide current range, providing high-quality audio sounds.
Features:
●Complementary to 2SA2223
●LAPT (Linear Amplifier Power Transistor)
●High Transition Frequency
●Bare Lead Frame: Pb-free (RoHS Compliant)
●VCEO --------------------------------------------------- 230 V
●IC ------------------------------------------------------- 15 A
●fT ------------------------------------------------------- 60 MHz
●PC ------------------------------------------------------ 160 W
The 2SC6145 is an NPN transistor of 230 V, 15 A. The product has constant hFE characteristics in a wide current range, providing high-quality audio sounds.
Features:
●Complementary to 2SA2223
●LAPT (Linear Amplifier Power Transistor)
●High Transition Frequency
●Bare Lead Frame: Pb-free (RoHS Compliant)
●VCEO --------------------------------------------------- 230 V
●IC ------------------------------------------------------- 15 A
●fT ------------------------------------------------------- 60 MHz
●PC ------------------------------------------------------ 160 W
I think with that die size you are 100% assured that they are fake.
The marking and lead frames for the fake power transistors are very convincing these days. A few months back I bought TIP35C and TIP36C which looked very convincing. But they tested like small/low current transistors.
The marking and lead frames for the fake power transistors are very convincing these days. A few months back I bought TIP35C and TIP36C which looked very convincing. But they tested like small/low current transistors.
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How small did they “test”? What was Cbe measuring on the fakes? I’ve seen a spread of about 2.5 nF to maybe 6 nF on genuine TIP35/6, with the higher values coming out of the China fab. Dies the same size, and had a decent amount of gain at 20 amps. They did switch processes a few years back on these, and you never get to see the die layout because the top cracks off with the molding so I can’t comment on any die layout differences.
Those fake C5200’s are about the size of TIP41’s inside. Among the smallest I’ve ever seen. Usually they are about 3055-size. I’ll bet they test less than 1000 pf Cbe.
The first thing we noticed was that Vbe(on) was way too high at currents well below what is listed on the datasheet. I don't have it in front of me but I seem to recall very low capacitance (as in under 1nF).
This is someone else's post but this looks the sort of stuff we received: Is this fake TIP35C?
I suspect that the fake TIP35C/36C, 2SC5200/2SA1943 and the fake D1047/B817 were all more like TIP41/42 class transistors. And the D1047/B817 looked like bad scrap/test rejects with some crazy low current gain and some crazy high Vbe numbers. (Barely a functional transistor.)
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Here is the link: My Transistors, original or copy?
In that link note the very small capacitance measurements for the TIP35C. Note that they are also strangely close to the measurements of the fake 2SC5200 that I had also bought online...
I think someone else once commented here that the fakes all have the same useless small die inside them. Just different packaging and marking. So I don't buy such components on ebay or AliExpress anymore. And I strongly recommend not buying op-amps, electrolytic caps, WIMA caps and low noise regulators/references there also!
In that link note the very small capacitance measurements for the TIP35C. Note that they are also strangely close to the measurements of the fake 2SC5200 that I had also bought online...
I think someone else once commented here that the fakes all have the same useless small die inside them. Just different packaging and marking. So I don't buy such components on ebay or AliExpress anymore. And I strongly recommend not buying op-amps, electrolytic caps, WIMA caps and low noise regulators/references there also!
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Well this is not a great method... ...but if all you have is one of the M328 transistor testers you can bend the E lead away and insert the B&C leads into the M328 tester and test those as a capacitor. Then you can bend the C lead away and insert the B&E leads into the M328 tester and test those as a capacitor.
That really is not a great method. But if you have a reference genuine device it can be a helpful indicator. For example I had a genuine TIP35C from an authorized distributor and the fakes measured almost 10x smaller capacitance. Clearly fake.
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My unsophisticated measurements using my DE-5000 LCR meter @100kHz
2SC5200
B-E, E-B 2.3nf
B-C, C-B 2nf
E-C, C-E 70pf
2SA1943
B-E 1500pf
E-B 1820pf
B-C 1475pf
C-B 1777pf
E-C 109pf
C-E 105pf
and for genuine
MJL4302A
B-E, E-B 11.5nf
B-C, C-B 6.3nf
E-C, C-E 1130pf
MJL4281A
B-E, E-B 12nf
B-C, C-B 7.6nf
E-C, C-E 666pf
The responsiveness to measurement is light and day between the fake and originals.
2SC5200
B-E, E-B 2.3nf
B-C, C-B 2nf
E-C, C-E 70pf
2SA1943
B-E 1500pf
E-B 1820pf
B-C 1475pf
C-B 1777pf
E-C 109pf
C-E 105pf
and for genuine
MJL4302A
B-E, E-B 11.5nf
B-C, C-B 6.3nf
E-C, C-E 1130pf
MJL4281A
B-E, E-B 12nf
B-C, C-B 7.6nf
E-C, C-E 666pf
The responsiveness to measurement is light and day between the fake and originals.