How to indentify counterfeit products of ST32F429i_Disco?

Posted on March 30, 2015 at 12:18

Hi Linda,

I have got a batch of very simple EEPROMs which seem to be pulling my SDA line low. The part number is

M24C02-RMN6TP

and as soon as I lift the SDA pin on the EEPROM the issue is fixed. This is a re-use of an older design and I would also like to rule out counterfeit parts. Hopefully, some-one from ST will reply on this.

Regards,

Paul

Posted on March 30, 2015 at 14:34

If you think you've got bogus parts you should a) contact your distributor, b) contact you ST sales rep. This is a user forum, this is unlikely to be addressed here.

The screens on the STM32F429I-DISCO boards don't travel very well, had several arrive in the initial batch where the screen and it's metal shield separated, or screen/touch didn't work.

Posted on March 30, 2015 at 16:02

Paul, 

If you have an osciloscope, you can mount a resistor in your SDA and SCL lines. If you calculate value to say 1/20th of your pullup resistor, you'll see 1/20th of VCC across your resistor. Watch both sides of the resistor and you'll know which side is pulling low on the SDA or SCL line. The 160 mV across the resistor should be clearly visible on the scope. 

Posted on April 07, 2015 at 00:17

Dear Clive1,

I have contacted the distributor, and filled the form according their instruction. But they just make me to wait, I have waited now already more than 1 month.

Is this company a qualified distributor? I have not seen them in your list of St.com:

www.FutureElectronics.com

Half of the devices did not work. some died when we were doing income inspect, some when we were doing programing, some in testing, some in the early life.

Thanks

Posted on April 07, 2015 at 00:57

I've worked with Future before.

As I've said the STM32F429I-DISCO boards don't travel well, even in the Continental USA via USPS or UPS.

Posted on April 07, 2015 at 01:21

if it don't travel well, after we put it into our products, what will happen?

I still doubt that they are counterfeit, because I bough from Newark before, they worked fine. But this time I bought from the company that I mention above, the problem comes.

Posted on April 07, 2015 at 07:23

Future is a very reputable company from Canada (yay). They would not knowingly sell counterfeit goods. They may not be as big as Newark, but they are definitely real.

In Canada we do not have ready access to counterfeit goods, like one would in Shenzhen, Shanghai (like my ''Rolex'' for $15), or in Mong Kok (SCO UNIX for $10 in 1988, with manuals). Ordering counterfeits would be just as much effort for Future as ordering originals, without the backlash that happens if you get caught.

And when ST's disco board prices are better at Digikey than buying off of Aliexpress(!), why would anybody bother with potential fakes?

Posted on April 07, 2015 at 14:26

Of curse it's possible to copy such complex chips, given one is willing to invest the required ressources.

In the '70 and '80, the Z80, MC6800, the i8008 and the i8086 were all reverse-engineered and copied in the eastern bloc. This bloc was an almost-closed economic zone, and copying was obviously cheaper than developing something different. (A sale was officially not allowed, think ''CoCom''.)

Is there someone with the required ressources, and a motive different from ''making a quick buck'' ? Faking discovery board is obviously not a profitable endeavour.

One (or at least I) would expect action from ST in this case ...

Posted on April 07, 2015 at 19:12

if it don't travel well, after we put it into our products, what will happen?

The customer will receive product that doesn't work? Isn't this something a design engineer should think through?

I think it's a combination of things, there's no rigidity or containment of the display on the board, the blister packing holds the edges of the board, it's not designed to hold the display in place. The boards have a tendency to warp, while the screens want to be flat. When I've developed stuff we have to consider it's construction and packaging, how masses are secured, vibration on socketed parts, and have to drop test things.

Our in-coming inspection routinely goes over things that arrive and returns defective/broken items immediately. If it's sufficiently bad the whole order goes back, and if the carrier broke the boxes, we'd take up a claim with them. Distributors have a clear understanding of this, and won't get paid.

If you think that this is an issue of counterfeit goods you're looking at the wrong issues, Future is not some fly-by-night Chinese brokering operation selling remarked chips.

Is there some reason that a) you can't deal with Future, or b) ST, directly about your issues? Remember this is a user forum.