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phostenix
Gold Member
USA
754 Posts |
 Posted - 09/22/2009 : 16:28:08
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I'm posting this here for people who never look at the ebay forum....
If you do repairs on power amps - guitar or otherwise - get educated on this issue of counterfeit transistors. ebay is the most common place you will find fakes. Counterfeit transistors are typically smaller transistors that are repackaged or re-labeled as more expensive or obsolete transistors. The power transistors are the worst, since they WILL fail under load (they're not capable of handling the current), usually taking out other parts with them & causing you to have to re-troubleshoot the entire amp.
BTW, ANY obsolete transistor is a target for counterfeiting, so if you're looking for matching transistors for an old Boss pedal & can't find the part number anywhere but on ebay - BEWARE!
Stick with the major parts suppliers that get their inventory straight from the factories. Even your local parts house is succeptible to this fraud. Most obsolete transistors can be matched to a new part number.
Reading material:
http://sound.westhost.com/counterfeit.htm
http://www.diyaudio.com/forums/showthread.php?t=71367
My fakes are pictured at the end of this thread (you must join to be able to see pics):
http://www.diyaudio.com/forums/showthread.php?t=5064
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Edited by - phostenix on 09/22/2009 22:55:11 |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 09/22/2009 : 17:34:29
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quote:
Originally posted by phostenix
I'm posting this here for people who never look at the ebay forum....
If you do repairs on power amps - guitar or otherwise - get educated on the issue of counterfeit transistors. ebay is the most common place you will find fakes. Counterfeit transistors are typically smaller transistors that are repackaged or re-labeled as more expensive or obsolete transistors. The power transistors are the worst, since they WILL fail under load (they're not capable of handling the current), usually taking out other parts with them & causing you to have to re-troubleshoot the entire amp.
BTW, ANY obsolete transistor is a target for counterfeiting, so if you're looking for matching transistors for an old Boss pedal & can't find the part number anywhere but on ebay - BEWARE!
Stick with the major parts suppliers that get their inventory straight from the factories. Even your local parts house is succeptible to this fraud. Most obsolete transistors can be matched to a new part number.
Reading material:
http://sound.westhost.com/counterfeit.htm
http://www.diyaudio.com/forums/showthread.php?t=71367
My fakes are pictured at the end of this thread (you must join to be able to see pics):
http://www.diyaudio.com/forums/showthread.php?t=5064
Hi phostenix
Will you please be kind enough, to upload those pics to the this forum.
It will help members here, that do not want to join another forum.
Thanks - Regards Dr. Bob
By the wayl Wait until you purchase 1000's of High-Cost custom processors & FPGA's.
And they are all fake.
What gave it away - besides the fact that none actually worked - over-heated until the solder joints on the BGA balls melted?
All the part numbers were PAD printed & wiped off with your thumb.
This cost us many hours of head scratching, hair pulling & gnashing of teeth.
Yes - & like you mentioned,
these came from a reputable 3rd party supplier, who also got caught with his pants down.
The real bitch, was we had to prove that the parts were counterfeit,
to recoup our costs from the supplier.
Who now has to recoup his costs from the overseas vendor.
Yes, they are a very large supplier of semiconductors & general components.
A couple of years back, were got caught with 2 seperate batches of QTY-400 & QTY-800,
2SD667A T0-92-2 transistors.
It appered that all the local suppliers had counterfeit of sub spec
stock of these transistors.
These transistors, are used in some 24V to 240VAC use on some fluro-inverters,
that we service.
They lasted about 30 seconds to 15mins, & were unable to switch fast enough, outputting less than the required Ac voltage to light the 15 watt fluro.
Worst part was that, the transistors overheated enough for some to actually catch fire. ( with real flames ).
I have also become aware of many fake NOS BBD's Bucket Brigade Delay Chips, that are used in Some Boss pedals.
The deal on these, if you are not getting these direct from Japan
They were never stocked of manufactured in China.
I do have worse stories, but I guess everyone gets the general picture.
I am concerned for the suppliers that are genuine & have genuine stock.
It's making it very difficult to know, who is trustworthy & who isn't.
Thanks for the heads up & reminder.
Regards Dr. Bob |
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RickBlacker
Bronze Member
USA
138 Posts |
Posted - 09/22/2009 : 19:46:01
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quote:
Originally posted by phostenix
Stick with the major parts suppliers that get their inventory straight from the factories. Even your local parts house is succeptible to this fraud. Most obsolete transistors can be matched to a new part number.
Who is a trustworthy site to buy from? |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 09/22/2009 : 20:42:26
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| I've had consistently good product from Small Bear. They even hand test some of the less common parts to ensure they are OK. |
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phostenix
Gold Member
USA
754 Posts |
Posted - 09/22/2009 : 21:29:45
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I've forgotten how this site will sometimes not work after you've typed a big response. [:(!)]
I will probably only buy from www.Mouser.com or www.Digikey.com from now on. Other distributors that I've seen get endorsements on forums are:
Avnet - http://avnetexpress.avnet.com
Farnell - www.farnell.com
BD Enterprises - www.bdent.com
I just recently got back to a project from several years ago where I had bought some Motorola power transistors from a couple of different ebay sellers. Yep, they're fakes, too. ebay is the #1 place to get ripped off with this - I find out now!
I am going to build a test rig now so that I can check transistors under load (with similar voltages & currents to what they will see in circuit). It's not enough to check them with a transistor checker or diode tester. If you use your amp as the test rig & they fail, you will be sorry! It ain't pretty & will damage more components and the PCB if things like resistors flame (they do). |
Edited by - phostenix on 09/22/2009 22:57:29 |
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phostenix
Gold Member
USA
754 Posts |
Posted - 09/22/2009 : 21:32:40
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quote:
Originally posted by Dr. Bob
I have also become aware of many fake NOS BBD's Bucket Brigade Delay Chips, that are used in Some Boss pedals.
The deal on these, if you are not getting these direct from Japan
They were never stocked of manufactured in China.
I was thinking about this the other day. I've bought quite a few of the BBD chips from Hong Kong sellers over the years. Now I need to setup a test rig for those, too. GRRRRRRR!! |
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phostenix
Gold Member
USA
754 Posts |
Posted - 09/22/2009 : 21:55:19
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Here are the pics of what I bought recently:
Front view of the 2SA1302 - the lettering is actually very accurate, including date code & gain (hfe) code.
Back view of the 2SA1302 - The exposed metal of the collectors is usually a mat finish, not this shiny, scratched up surface. On some poor counterfeits, the metal will not be flat, or it won't be a proper rectangle shape (not square). These look pretty good.
The plastic (expoxy) cases on these are poorly made. Notice the voids around the edge of the collector.
This one cracked open VERY easily. Noticed that the ssemiconductor die came off the collector & stayed embedded in the plastic. It's WAY too small for a power transistor that is rated for 15 Amps!
The calipers show mm on the shaft & inches on the dial.
Front view of the 2SC3281 - the lettering is accurate, including date code - BUT, there's no gain (hfe) code.
Back view of the 2SC3281 - more shiny & scatched collectors.
This one was a little harder to crack open & you can see the die much better, including the wires that attached to the base & emitter legs. Still way too small.
The calipers show mm on the shaft & inches on the dial. |
Edited by - phostenix on 09/22/2009 22:53:41 |
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phostenix
Gold Member
USA
754 Posts |
Posted - 09/22/2009 : 22:01:27
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Here's a pic I found on another forum of a fake vs. real 2SA1302:
Real one on the right - fake is missing the gain code & has additional numbers at the bottom that Toshiba doesn't do. |
Edited by - phostenix on 09/22/2009 22:02:53 |
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phostenix
Gold Member
USA
754 Posts |
Posted - 09/22/2009 : 22:05:14
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| BTW, opening them was as easy as laying the transistor on its side on a hard surface and putting a sharp chisel on the seam on the edge of the transistor. A quick whack with a hammer and ,voila, 2 pieces. |
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phostenix
Gold Member
USA
754 Posts |
Posted - 09/22/2009 : 22:14:33
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Just to show you how ridiculous this counterfeiting goes:
More pics of fakes here:
http://transfal.tripod.com/
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nathanscribe
Silver Member
United Kingdom
376 Posts |
Posted - 09/23/2009 : 01:04:18
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I've had a small number of BBDs off ebay, but so far they've proved OK. I won't be using the seller again though after bad reports. Small Bear in future.
Why would anybody bother faking a cap????? |
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Laurie
Double Platinum Member
Canada
4854 Posts |
Posted - 09/23/2009 : 01:28:39
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quote:
Originally posted by nathanscribe
Why would anybody bother faking a cap?????
My very question... what's in this financially? Pennies? |
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phostenix
Gold Member
USA
754 Posts |
Posted - 09/23/2009 : 01:51:38
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Here's a good answer to that from the DIYAudio forum:
"Like where did this melamine tainted gluten that found its way into pet food come from?
From small to medium size companies in countries with little to no care for who they rip off and are desperate for western currencies.
Goodness knows it's easy enough to do ... get some metal to fabricate a heatsink, buy cheap transistors to put inside the case so the leads show something like correct characteristics then pot them in epoxy and paint the numbers on.
Then you sell them through middle men who will take the fall. Or sell them through things like ebay (sadly, while ebay is brilliant, it's also a terrific way to market knock off products). If a large electronics distributor has need of particular components and he sees a supply available, he'll buy to meet that need, not always checking quality or source. Of course, if he asks for samples, they'll send a few of the "real thing"."
http://www.diyaudio.com/forums/showthread.php?t=82638
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zerksies
Double Platinum Member
USA
3406 Posts |
Posted - 09/23/2009 : 14:12:02
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| i really don't see the point in making counterfit parts what kind of money are you really gonna make |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 09/23/2009 : 14:29:07
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Hi phostenix
Thanks for your PM asking how to post pics on the forum.
I thought It would be better to reply on the forum.
That way lots of others get to read the How-to as well.
In out FAQ section
there is a Thread called:
How to display Pics-Images on the Forum
Here is the direct link.
http://www.bossarea.com/forum/topic.asp?TOPIC_ID=4015
I hope this helps.
I saw from the links in your post, that you are hosting the current pics on your server.
If you upload them to here, you can edit your previous posts to reflect the new link on bossarea;
And free up the space & bandwidth on your server.
If for some reason you are unable to get the pics to display.
I will be only to happy to add the HTML code snippet to your posts.
You will then be able to see the display HTML, if you go back click on edit.
Thanks for sharing the Fake pics with us.
It's really obvious on the first batch that they are poor quality Fakes, just by looking at the poor plastic molding.
The fake "cap in a cap", reminded me of cheap fake batteries I have seen,
where they place a cheaper sub-quality AA penlight into a C or D shell.
This is typical with the "Deal of a Lifetime" 5000mAH Plus, D cells.
Overall It's a sad situation.
In our case it was on of the bigger reputable vendors, ( one that's on your list),
that was caught out with fake 2SD667A T092-2 transistors.
So not even the bigger reputable vendors are immune.
At least the reputable vendors, will refund or replace you money-parts,
once you agree that the parts are faulty or fake.
Regards Dr. Bob
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Edited by - Dr. Bob on 09/23/2009 14:31:21 |
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phostenix
Gold Member
USA
754 Posts |
Posted - 09/23/2009 : 15:54:34
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quote:
Originally posted by zerksies
i really don't see the point in making counterfit parts what kind of money are you really gonna make
If you can sell hundreds or thousands of units of something & bring in western currencies, you can make enough money to survive in a lot of countries around the world. |
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Counterfeit Transistors
