How to Spot Fake Semiconductors (http://sound.whsites.net/counterfeit.htm)
Date: Tuesday, September 13 @ 12:01:01 UTC
Last Updated 12 Apr 2004
This section has been moved from the editorial, since it is an important topic in its own right. The list
must not be considered comprehensive, as I am sure that there are a great many additional counterfeit
devices available that have either not been discovered yet, or whose purchasers are too embarrassed by being "caught"
by the fraudsters, and are unwilling to admit that they were robbed.
| Elliott Sound Products
Counterfeit components identified so far
|I would like to thank those who have sent information, photos or links to other sites about fake devices. Your continued vigilance will help the fight against these practices. It is a fight that we cannot win, but at least by knowing what to look for, and where the problems have been found, there is at least some hope that we can make it harder for the criminals involved.|
... and just in case you thought that this was a conspiracy affecting hobbyists, read this article from
EDTN - the cost is in millions,
and that's just in the US!
12 April 2004: From the UK, Mark W has provided the following ...
I regret to report to you that you may now add 2SA1943 to the list of possibly fake transistors.
- MJ15003/4 Power Transistors
- OP-07 Op-amps
- 2N2773 Power Transistors (probable)
- 2SA1302 and 2SC3281 (Toshiba) Found all over the world! The ones seen are all marked Toshiba.
- NTE37 and NTE37 (I am told these are equivalent to 2SC2581 and 2SA1106) - not confirmed, but highly suspect
- LM3915 LED VU Meter
- Sanken 2SA1216 (and presumably the NPN type 2SC2922) - Other similar "Sanken" devices may also be affected
- Toshiba 2SA1943 and presumably 2SC5200 - this had to happen, and was only a matter of time.
My story will probably sound familiar. I was powering up an amp of my own design (more or less) for the first time when the fuses blew. I removed the output devices and discovered that one had failed short. I checked the schematic and the pcb layout for design/construction errors. I did this twice. I first decided that the fault was mine since earlier I had a small problem because of forgetting a sil-pad (though not on the failed 2SA1943). But also felt that the circuit and layout were essentially OK - it wasn't THAT original. I try to power up again and when the rails reached Â±35V the prior story repeated. I was still inclined to suspect my own ineptness but on a lark, I smashed open one of the 2SA1943's if only to alleviate my frustration.
This was a foregone conclusion - I knew that the criminal bastards would go for the latest Toshiba devices sooner or later, but I must admit I'm a little surprised that it took them so long. This means that it is inviting disaster to use any Toshiba power transistors unless you are 100% certain of the source - unlikely in the extreme.
This is a pity, because they have a very good performance (well, the genuine ones do), but the criminals have once again ruined the reputation of a perfectly good transistor, and created a situation where it would be folly to use them in a design.
25 May 2003: From Singapore, Michael Chua provided this information ...
I won't send the samples. You could mention however that one visual characteristic of the fakes is that the Toshiba making is on a smooth shiny rectangular area of the package. On the fake it is easier to read the markings than the real ones.
What I found looked exactly, I MEAN EXACTLY, like the photo on your site of the inside of a fake 2SA1302. I conclude it's the same bastards just
printing a different label on the package, At first I just thought I couldn't find the die or didn't know what I was looking for. Then I saw this 3mm x 3mm square thing pasted on with white glue. There is a clue on the outside. On a real one (I sacrificed one just be sure) the Toshiba label is typically hard to read on the dull surface. On the fake the surface has a glossy area where the label is quite clear.
The 2SC5200s from the particular supplier seem to be real. They don't die when abused and the exterior is dull flat black, somewhat difficult to read unless the light is right.
I can only assume that the metal backing plate is slightly thicker in the fake, so that the weight of each unit is reasonably similar. This will not necessarily assist heat removal though, and these fake devices would be lucky to withstand 100W dissipation (based on tests I have done on other fakes with a similar die size).
When I asked if it was ok for me to "borrow" the info from his site, Mike sent me the following e-mail ...
||The Sanken on the right is the original part in each photo, with the fake on the left.
Obvious Features of Original (Front) ...
1) The lettering is thicker and smaller.
Less Obvious Features (Front) ...
2) The production run number is in the middle, below the part number.
3) Overall size - the original is slightly bigger, about 0.5mm on either edge.
4) In the originals, the angles are not as sharp (slightly rounded).
Obvious Features (Rear) ...
1) In the original, the back metal plate is slightly frosted.
Common Features: Both weigh approx 10 grammes.
2) The fake ones are shiny, almost a mirror finish.
||... And when cracked open, the difference is very obvious
1) When cracked open, the die on the original is attached to a TO3P type heatsink which is in turn bonded to a larger heatsink contact face.
It is difficult to tell exactly, but the die in the fake looks to be around 3mmÂ² which seems to be a common feature of most of the fake devices seen. That it is a great deal smaller than the original, and that it has less ability to spread the heat to the metal heatsink face is quite apparent.
2) The the die in the original is much larger.
I am delighted with your offer. For the sake of the audio community, it is important that these people are exposed. I was told these fakes originated from China. What surprises me is how close they are to the real thing. I will keep you posted if I come across more fakes.
See the original page at AmpsLab, and my thanks to Michael for allowing me to use his photos and info. If these are available in Singapore, you can guarantee that they will be in wide circulation very quickly, since Singapore is a major distribution centre for Asian semiconductors.
23 Jan 2003: Alleged NTE devices have been found in the US (NTE36/37) that failed instantly, and just to add insult to injury, took the bridge rectifier and transformer with them. An edited quote from the reader who found these latest "gems" ...
I just got done reading your article on the counterfeit semiconductors and it all clicked for me. A little while back i was repairing an old amp of mine and purchased 2 pretty expensive matched pairs of BJT's from here in the States. NTE37 and NTE37 are the same as C2581 and A1106 devices. Well these NTE brand semis looked weird to start off with - one transistor of a matched pair was in a green case but the rest were in black ... under the NTE36 and NTE37 I could see a shadow of a device number on each semi that had been taken off. I had no clue about this counterfeiting thing at the time and put them in my amp - they immediately burned out but this time it took out the transformer and rectifiers with them. I thought i was just loosing my touch at fixing stuff at the time but now i see what the real problem is 'cause I cracked open one of the cases a few minutes ago and it definitely didn't look like the original
semiconductor die. Tomorrow I'm going to contact the supplier and let them know, because I paid them US$40 for 4 transistors and ended up with about US$150 in damage.
Counterfeit transistors cost far more than their monetary value - loss of confidence, time, "collateral damage", etc. are far worse. This is one of many stories I hear typically about once or twice a week, and the only difference is that in this case, a new target for the counterfeiters has been found. I doubt that the supplier has deliberately supplied fake devices, but the fact remains that they have counterfeit stock and people have been affected. All suppliers should, nay must be advised immediately if you discover counterfeit devices. It is most unfortunate that so many suppliers have their heads buried so far in the sand (or see below
) that they will not believe their customers. It may help to direct them to this page, but some are so far gone that they refuse to believe that counterfeiting even happens!
For every e-mail I get on this topic, there will be hundreds of other people who don't know about this page, and who think that the mistake must have been theirs - this is a sad situation indeed!
A reader in Sweden sent me some pictures of fake Toshiba devices, purchased from a local dealer - this shows just how bad these counterfeits can be ...
Notice in particular the rightmost picture - the transistor base (the heatsink surface, not the internal connection ;-) is so convex that it won't sit even close to flat. In this case, there is about 0.5 mm convex curvature, which is so completely unacceptable that words fail me!
I have heard other reports of bases that are concave, so the device will never make proper contact with the heatsink, but you can't see it. Either is unacceptable (in the extreme). The printing on the 2SA1302 looks like it was done with a felt-tipped pen (well, maybe a little better than that) - not quite what one expects from a reputable manufacturer, is it? These devices passed the acetone test, so the markings are quite permanent (not all
do though - the printing can be removed quite easily from some fakes).
This is an appalling state of affairs. I also recently had an e-mail from a reader in the UK. He built the P68 subwoofer amp, and was only running it into 8 ohms and it failed. After a quick exchange of e-mails, it transpired that he purchased some "Toshiba" devices from a local supplier for less than the normal price - say no more! His first set came from a reputable dealer (but not the distributor), so almost no-one can be trusted on this score.
From New Zealand
Nice and Flat? Not Likely!
A reader sent me a sample 2SA1302 and 2SC3281 to test for him, after his P68 sub-woofer amp blew up during quite gentle testing. The 2SA1302 died well before I could reach my target of 5A at 30V (the limit of the SOA curve for these devices for steady state current at that voltage). The tests were done with the transistor firmly clamped to a heatsink, and were of short duration to prevent the die from overheating - but it still failed!
Someone must be joking!
The die is 2.5mm square! This is tiny, and I am actually surprised that the transistor managed even to get to 2A at 30V before it blew. This is well short of the specification, and obviously the reason the amp failed. One can hardly expect a 60W (at best) transistor to provide close to 120W output (the approximate power expected from each pair of devices). Naturally, the devices that I was sent were clearly branded as Toshiba, and are just as clearly fakes.
The 2SC3281 actually managed to survive my SOA (Safe Operating Area) test, but given that the printing was almost identical to the other device, I would be highly unwilling to trust it - it may well be genuine, or simply a "better class" of fake. There were also subtle differences in the case construction of each device, with the 2SA1302 being almost identical in all respects to the Chinese devices that I have (not branded as Toshiba, but also incapable of the rated power during an SOA test). The 2SC3281 was different from any of the other samples I have.
Just in case anyone was wondering, I know it's not my P68 amp design, since I would have had a great many complaints by now if the design were flawed, so that only leaves the transistors as being highly suspect. My original amp works fine as well, and has been "punished" many times without failure.
Please take great care when buying semiconductors - especially "premium" devices. Since these have the highest markup (i.e. they are fairly expensive), they are the ones most likely to be fakes.
The Main Story (so far) ...
So, off you go to the local parts shop to buy some transistors (or indeed, other parts!). Having decided that MJ15003/4 devices fit your needs (these are rugged and powerful devices), you hand over a not insubstantial amount of cash and head home to build the masterpiece. Inexplicably, the expensive output transistors fail, but you know that their ratings are well within the design limits for the project you are building. This happens once,
maybe twice, or perhaps more. You get discouraged, and shelve the project - having already spent quite a lot on all the parts needed.
Even worse, during testing, the transistors are (or seem to be) fine, only to fail later taking your expensive speakers with them. Now it is really serious.
So is the problem a bad design? Very probably not. It has been brought to my attention that counterfeit power transistors are available (again!). Don't bother re-reading that - you saw it correctly. Counterfeit power transistors!!
The first instance (that I know of) of this was in 1980, when MJ15003/4 transistors were sold under the brand name "TIC". These, and many similar counterfeits were in fact 2N3055 and MJ2955
aluminum cased devices, and they (the counterfeiters) had removed the original markings and screen printed the fraudulent type numbers on the cases. Why? Because 2N3055 and MJ2955 devices are cheap, and genuine MJ15003 and MJ15004 transistors are not.
My informant tells me that only recently someone in New Zealand bought some "MJ15003/4" transistors with an amplifier kit, and they failed. A reader (also in New Zealand) was caught with fake 2SA1302 & 2SC3281 devices, causing his P68 sub amp to fail (as described above). In the meantime ...
I have asked one of the local suppliers (who was inadvertently selling counterfeit devices) to check the authenticity of their stock. I will not name the
suppliers, as it is quite probable that they are innocent, and have been defrauded along with everyone else. Needless to say, I cannot do this checking with any supplier outside Australia, as I do not have ready access to the components they sell or to anyone who might know something.
This Australian supplier (so far) has a "Stop Sale" on their computer for these devices, so it has been noticed by them, at least. In particular, look for a manufacture code of MEX190, with the date code 9H34. Some of the counterfeit devices even have the wrong polarity (an NPN MJ15004 - I don't think so!).
Double Headed Duds!
- Beware of MJ15003 and MJ15004 transistors in aluminum cases (genuine Motorola [now On-Semi] devices use steel cases, and have done since 1982). Don't count on this, though - there are fake Motorola devices in steel cases too.
- Test the markings with a solvent (such as acetone - nail polish remover). Most genuine transistors are marked with non-removable ink, counterfeit devices may be marked with normal screen printing ink that comes off easily.
- Test the breakdown voltage with a transistor tester if one is available. Genuine devices are rated at 140V, but will usually be higher than this. Counterfeit transistors will generally have a much lower breakdown voltage. The latest batch will actually pass this test !
- Ask for confirmation from the supplier that the devices are genuine. Feel free to refer them to this page if they claim you are mad :-)
I have been advised that the frauds - or at least some of them - have two transistor silicon dies internally, wired in parallel in a desperate (but futile) attempt to meet the specifications. These are both quite small for the claimed power rating, and are directly bonded to the steel case. The use of two dies is in itself most unusual, but they are not even bonded to a copper "coin" (heat spreader) as is the normal practice, so thermal transfer will be much worse than it should be, and thermal expansion coefficients possibly place the silicon at much greater risk of cracking - not from anything the user does, but from normal heating and cooling cycles.
I managed to convince the salesperson at an electronics outlet to sell me one of the "MJ15003" devices, despite the "stop sale" warning from the computer. This is fine, since I already explained why I wanted one. Most discouraging was that the salesperson obtained "advice" from someone else in the store that the one I had (MEX190) was genuine. Well, excuse me. There were some others in the drawer that looked as if they might be real Motorola devices, but not these.
I got it home, and promptly ran some tests before I cut the top off. Gain was (barely) passable at 25 at 0.5A, and the breakdown voltage was above the 140V rating. Then I removed the top, and guess what I found? If you said "Two dies?", you are quite correct. They are exactly as described to me - two small dies, bonded directly to the steel case, and wired in parallel with what I thought were rather flimsy bonding wires. The whole construction was coated with a thin layer of silicone.
I have e-mailed Motorola for more, and to find out if this is a construction method they have ever used. No answer has ever been received, but I think I already know the answer.
Given the sophistication of this fraud, it seems more than likely that these transistors are made in a proper fabrication plant, rather than just being
relabeled junk or factory rejects. The construction overall (of my sample at least) was quite neat, and was obviously performed with the proper equipment - if I were to go to that much trouble, it would be worth the effort to use the correct die in the first place! This begs the question of where they come from, and I for one would be very interested to find out. From the latest information to hand, China and India are implicated.
One way to be sure that you have the real thing is to buy ONLY from accredited and
authorized Motorola or Toshiba (or whomever) distributors. This may be irksome for home constructors, as these dealers usually have a minimum order value (locally it is AU$100 but will vary in different countries). It is not known at this stage how widespread the rort is, but since I have (over the last couple of years) received information from the UK, USA, Canada, New Zealand, Sweden and India about similar rackets, we can justifiably assume that no-one is safe. If anyone has further information to add, please
Some info received from a local supplier in response to my e-mail (reproduced verbatim) ...
Dear Mr. Elliott,
There was some more information regarding store policies that I shall not disclose, since this may identify the supplier to locals, at least. I was suitably impressed with the explanation and the efforts taken to fix this problem, and can only hope that other suppliers are equally responsive.
New: Oct 2000 Dick Smith Electronics Issues "Motorola" Recall Notice
Thank you for your email regarding the above matter. We have already been alerted to the problem about a couple of weeks ago when it was first noticed that some of the MJ15004 were found to be incorrectly
polarized - that is, NPN instead of PNP. Our suspicions were raised and we proceeded to cut the devices open, finding their internal construction to be as per your description. Not only that, the chip dies were smaller than the known genuine Motorola types and the internal finishing was abysmal - not the usual high standards that is expected of a Motorola device. The counterfeiters were, fortunately, not too professional and it was possible, on close inspection and comparison to a genuine Motorola device, to tell them apart.
From our knowledge of Motorola manufacturing processes, such a shoddy quality would never have been passed and they are definitely not from Motorola. Upon ascertaining this, we contacted Motorola or rather, ON Semiconductors in the U.S. and notified them of the counterfeits. Together with that, we also provided them with whatever information we have on hand regarding the source trail of our stock which came through a local Australian importer who brought them in through an until-now trusted source in Hong Kong. We have little to doubt the trustworthiness of our supplier as we have been dealing with him for a number of years without any problem encountered. From ON Semiconductor's reply, it would appear that they are already aware of the existence of a counterfeit ring operating out of India and China. We have left any further investigations that ON Semiconductors may want to carry out with them on an international level.
Australian electronics retailer (and wholesaler) Dick Smith Electronics has issued a recall notice on the fake Motorola transistors, and provides a detailed description of how to identify the genuine article from the frauds. This is a good move, and offers some hope to the poor purchaser, however so far no-one else has even acknowledged that this fraud exists, despite that fact that at least one Sydney based firm is still happily selling the counterfeit devices. This is a shameful situation, and one that I would like to see corrected as soon as possible. I am not about to hold my breath, as I expect it will be a long time (if ever) before the others admit their mistake (assuming that it actually was a mistake!)
To all other resellers world wide ...
Come clean, admit your mistake, or prove to your customers that you have never stocked counterfeit components. Please! This is not a big thing to ask, and will go a long way to proving that you value your customers and their custom. If not, you will be seen as the baddies, and rightfully so if you continue to defraud your customers!
These are the external (visible) differences between the real and fake devices. There are almost certainly additional variations (the counterfeiters will be aware of this variant by now), so extreme vigilance is needed.
In many cases, the tops of the fakes can be popped off quite easily - this should be an almost impossible task with genuine devices from Motorola and ON Semiconductor.
Where (or What) Next?
I received an e-mail from a reader in India, who purchased some premium op-amps (at a premium price, naturally). Having paid for OP-07 op-amps, one would be disheartened to put it mildly to discover that they were really 741s. I don't know if this has happened anywhere else, but it is fair warning that you could be next.
And the Saga Continues ...
Now we have Toshiba branded 2N2773 power transistors. This in itself is interesting, as a search on the Toshiba site reveals that they don't even seem to make this transistor! It would be unusual for a Japanese manufacturer to make a "2N" device at all, but doubly so since this is a very old device now, and seems to be discontinued by just about every other maker.
Again, these have all the "earmarks" of counterfeits - and naturally enough someone was caught out, and his amp failed with these transistors installed. If you happen across any of these components, be afraid - be very afraid!
From a reader ...
"Add 2SA1302 and 2SC3281 (Toshiba) to your counterfeit list. I found them (counterfeit ones, that is) here, in dinky Malaysia! The ink printout is totally different from the real thing, being WHITE in
Toshiba plastic transistors are usually marked in white, so this could be misleading. However I do know for a fact that Chinese (unbranded) 2SA and 2SC devices are available, but these make no pretence at being Toshiba. Perhaps someone has bought the Chinese ones and "branded" them as Toshiba - a worthwhile effort for the criminal element, since the Chinese devices are quite cheap.
Since the Chinese devices are not branded, they cannot be deemed counterfeits, but what sort of quality you could expect is anyone's guess, so one should be wary. It is possible that these transistors are OK, but equally they may be completely useless.
Further Update (06 Jan 2002)
I have checked the Chinese versions, both a load test and visual inspection. The device I checked blew up at well below the normal peak power, and a look at the innards revealed a silicon die about 3mm square - too small for the do*****ented power rating.
On the positive side (if there is one), at least the base plate was copper, and passably (!) flat, unlike the new fakes shown above. These devices would probably be OK in a low power amp, but cannot be used at anywhere near the full capabilities of the real Toshiba transistors.
Are these being purchased by the unscrupulous and re-labeled as Toshiba - you can count on it !
The photos above are indicative of what you will find inside a couple of typical fakes. The MJ15003 has two dies, each about 3 mm square, and simply wired in parallel. As can be seen, there is no heat distribution "coin" - they are simply bonded to the steel case. Motorola (or ON Semiconductor) has never made a power transistor in this way (to my knowledge, or that of anyone else I've spoken to about the fakes).
The situation with the 2SA/C devices is a little less obvious. The silicon die is just visible under a layer of silicone (the emitter and base leads came away with the epoxy, which is why you don't see them). The die is again 3mm square, and is bonded directly to the metal tab. In this case, the tab is of copper, so that part is acceptable. Unfortunately, I don't have an original device for comparison, so if anyone does (preferably a blown one - they are too expensive to sacrifice), I would appreciate a photo or even a description of the insides.
One thing that is known, is that Toshiba has not made 2SA1302 and 2SC3281 transistors since 2000 (or thereabouts), so the chance of obtaining genuine devices is very low. I suggest that MJL1320/3281 or the current Toshiba 2SA1943 and 2SC5200 be used - I have not heard of fakes of these devices (yet!).
... And Still They Come ...
From a reader in India, and reproduced (almost) verbatim:
MJ15003 - Typical
I was reading the article about duplicate/fake transistors. Well, they started faking ICs too!. Don't get me wrong though. I live in India. In my best knowledge, there are no IC/Transistor making factory anywhere in India. So I don't think the fakes are MADE here. But there is a possibility that India is a kind of
The above was actually received some time ago, and I forgot about it. I have now remembered :-) As you can see, this is widespread, and many store owners are unlikely to admit that they have fraudulent stock.
I think I can say with reasonable certainty that this is the tip of the iceberg. How much reject stock (factory 2nds, out of tolerance, incorrectly marked, etc) is gathered up by unscrupulous dealers and sold off as 1st quality? My guess is - a lot.
Always remember ... Any deal that seems too good to be true almost certainly is too good to be true!
06 Jun 2001 ... and now, two more reports (reproduced verbatim)
The real purpose of this mail is to add one more IC to the known frauds. (Hundreds more maybe there). I bought this IC, LM3915, supposedly made by National Semiconductor for your LED VU Meter project. It costs about 50Rs (our currency, that's about $US1.00 ). But it burned out the instant I connected it to the 15-0-15 supply. I bought another one from another store. It looked a bit different. Anyway after reading your article, I got suspicious. I used a simple knife to remove the top cap like thing of the IC (Normal ICs cannot be stripped like that).
I found another IC. When I scratched the silicon, I saw what I was expecting, LB1405. A vastly inferior (in my experience) and cheap IC. I got ripped by 5 times the cost. I might not have found out this if I didn't power it with 15 volts. I don't know how 'THEY' managed to do this. But it wouldn't have worked anyway. The pin configs are very different. I showed it to the store owner. He discarded it as my mischief. But I couldn't help my poor friend
who was making a 10 channel EQ. Poor fellow. He burned out all of the ICs he bought from this store. He doesn't have the budget to replace all the chips. So he's using the EQ without the VUs. Poor chap.
From South Africa ...
I live in South Africa and build audio stuff for a hobby (sometimes making the odd amp for a friend and I am presently finishing a friends amp.) I was surfing the web and stumbled onto your site again. Having looked through all the project stuff, I finally went onto the editorials and came across the counterfeit transistor story.
Note: The JPEG image I was sent confirmed the devices are fakes :-(
... And Canada ...
The hairs on the back of my neck started to rise the more I read because the amp that I am finishing is using MJ15003/15004 output devices, but I was at work and had to wait till I got home to check what devices I have installed in the amp. Needless to say they seem counterfeit, see attached jpeg image file, with MEX190/MEX1CO as the place of manufacture and 9H34/9R32 as the date codes (as per Richard Freeman's email to IndustryCommunity.com). I have as yet to open these device but I am sure that they will have two dies internally, when I get the time I will open them and take a photo of the internals. So the counterfeit devices are not only confined Australia, but are probably available throughout the world.
About three weeks ago we received a batch of transistors from Digikey... To be more specific:
2N3773's... (about... 100 of them at $1.25 ea.)
The only thing I can suggest is that you exercise extreme vigilance when purchasing semiconductors, and especially the "premium" devices. If they are normally expensive, then they are ripe for counterfeiting, since the potential gains for the criminals behind these rackets are very large indeed.
In the case of resellers, they are tempted by the low wholesale prices, since they see a way to
maximize their own profits. The backlash is that their customers will be bitterly disappointed, and will very likely take their custom elsewhere - a classic no-win situation.
Be more than careful with devices offered at auctions. Not all will be fakes, but you can almost guarantee that a fair proportion are counterfeit. I have had e-mails from a number of people who have purchased semiconductors at various on-line auctions, and the results were entirely predictable. The devices bought were fakes, and there is little or no recourse with an on-line seller who can happily disappear after unloading the goods.
Even some of the more established sellers will (inadvertently or otherwise) offer counterfeit components. Don't assume that semiconductors are the only parts that are affected - a great many polypropylene capacitors are nothing of the sort (they are polyester or mylar), and virtually anything that can be made to look like a more expensive part will be. Even though the individual gain may be small, if an unscrupulous dealer can make an extra ten cents on 10,000 parts, this represents a very worthwhile profit from their perspective.
Counterfeit components are not only those that are re-marked with a different manufacturer's logo and/or part number - no-one has been able to categorically deny that "bad" batches of parts (where something went wrong in the manufacturing process) are destroyed. The most likely situation is that they are auctioned off as scrap, except the scrap metal merchants may well see a golden opportunity to make a lot more than the would by melting the parts down for their metal content.
Does this actually happen? I honestly don't know, but I would be much more surprised if it doesn't than if it can be proven that it does not.
Genuine Motorola / ON Semiconductor Devices
For the record, the following photos show the genuine articles. This is (again) a less than comprehensive gathering, but these were submitted by a reader for inclusion, as he figured that it would be nice if people could see what these devices should look like.
I have worked with the original MOT's and I know the way they are built and labeled. These "new" parts, didn't look like anything I have ever seen, and I have been in this field for almost 20 years working in audio related goodies.
The Manufacturer: MEV (you tell me if you know them)
Case: Steel or something like that
The finishing: lead immersed. the whole case looked as if it had been immersed on molten solder to "give" it a "silver coat" look alike. (the pins even looked as if they were used devices and had been cleaned off to strip excess solder material.
The label (markings): looked like cheap paint barely stamped onto the top of the case. some acetone and it rubbed off. (YIKES!!!) And it looks like this:
And, if this wasn't scary enough yet, here's the best part of the movie...
I installed one new pair on a switching amp used on a GE servo. Each board makes 1 half of an H Bridge. So a total of two boards are necessary to form a dual direction servo unit (Each amp uses a total of 12 2N3773's for a total of 90 Amps at 90Vdc, at full load when the trannies are completely either on or off depending on the direction of rotation) all the original devices on the amp were ok, except two that were shorted. After double and triple checking of the board, I installed it on a test bench we have built. (to simulate the working conditions required by GE's service manuals).
The "new" trannies lasted 15 seconds... they started off fine and gradually deteriorated until they went off with a bang!!! The rest is history... replaced them again with two more from the same batch and they worked for an hour...
So I decided to crack the first pair open... (considering i had read your stories on your website...) The Dies are smaller than those of a 2N3055. 25% smaller than the original Motorola devices.
Silicon is Silicon any way you slice it and (normally; did I hear... counterfeit???) current densities are the same from one device or manufacturer to another... Regardless of it's use or purpose. Once you go beyond this set parameter, you're in trouble. Even worse if the TO-3 case (like this aforementioned device) has a coin no bigger that 1 CM wide by 2.5 mm high. (Yes I love Metric system too.)
Footnote: I just remembered another device I ran into that same day... A 2N3055 (supposedly MOTOROLA, as it was labeled. Yet the ink used for the label was the cheap kind.) that looked almost identical to a genuine MOT device, BUT it was made in MEXICO. So far that sounds believable... Right???
Wrong!!! I opened the casing after i had blown one up at only 6 amps, and came to see that the die was slightly bigger than that of a TIP 41C. Like I might have said before, I know very well the dies in these devices. I cracked many of them open to see their guts after they blow. Weird, eh? No coin, or any internal heat spreader at all. The chip looked like it was glued to the case. No traces of the usual solder material that's normally used.
My dear friend...
As much as I love my hobby and my profession (which happens to be the same. I HATE THIS CRAP!!!! (Excuse my french!). I mean... seriously. What's next?????
Let's hope that someone sees this and takes some action!!!. I am, and WILL do my part! I hope this matter (someday) might be resolved, or at least tamed. (Yeah, right.)
I apologize for my rather dry sense of humor. Yet this is no laughing matter. Please feel free to modify this email at your will and post it on your site (if you feel it's worth the effort.)
Some Examples of "The Real Thing"
Click either image to enlarge - they are fairly big photos, and will take a while to load if you are on a dial-up connection. It is worth the effort though, just so you can see some real samples.
Page created and Copyright (c) 14 June 2000 Rod Elliott. Updated Apr 2002 - moved section to its own page.
|Copyright Notice. This article, including but not limited to all text and diagrams, is the intellectual property of Rod Elliott, and is Copyright Â© 2000-2004. Reproduction or re-publication is allowed due to the importance of ensuring that everyone should be aware of these fraudulent practices, on condition that the name and URL of the original page and author (Rod Elliott) of the information herein is not removed or replaced.