Counterfeit NAND ICs?

[lookimback]

So, I bought these NAND memories a few months ago on AliExpress. They were supposed to be Hynix HY27US08561A. I finally decided today that I'd finish the Sanyo DP42849 which has been buried behind dozens of other TVs for several months. So, I got my programmer out, and after several hours of trying to get it to work (@$%#& Windows 10 update @$%#& breaking everything!) I finally got it working again and found that the memories were not recognized. My programmer (GQ-5X) was saying unknown device and showing EC 75 A5 BD as the device registers. Well, I knew EC was Samsung's JEDEC ID, so I suspected something was wrong already. I Googled the device registers and found the memory to actually be a Samsung K9F5608U0x. I created a device definition based on the data in the datasheet and the programmer recognizes it. They seem to be identical, I'm hoping I can still use them.

[Sparkey55]

Re: Counterfeit NAND ICs?

It would surprise me if anything from AlieExpress was real!

[fzabkar]

Re: Counterfeit NAND ICs?

There appears to be a difference in the PRE pin. It exists in the Hyundai part but is NC in the Samsung. Also, the Samsung has an additional GND pin (pin #6) which must be grounded. If you don't ground this pin, you won't be able to read the spare bytes. Pin #6 is NC for the Hyundai part.

BTW, how can you be certain that the data you are reading from the original part are not corrupt? Do you have any way of testing the ECC?

[lookimback]

Re: Counterfeit NAND ICs?

BTW, how can you be certain that the data you are reading from the original part are not corrupt? Do you have any way of testing the ECC?

I bought a new memory a while back and got a read dump so I wouldn't have to spend $30 every time I needed one of these.

[fzabkar]

Re: Counterfeit NAND ICs?

Each page of the NAND IC consists of 512 bytes + 16 spare bytes. The spare area would normally contain ECC bytes for error detection and correction.

If you simply read the raw data plus ECC and then write it back, you will be making copies of any errors. You need to correct the raw data for errors, recompute the ECC, and write back the error-free data to your new IC.

[Agent24]

Re: Counterfeit NAND ICs?

You're lucky it's even an IC and not just a blob of lead!

[lookimback]

Re: Counterfeit NAND ICs?

Each page of the NAND IC consists of 512 bytes + 16 spare bytes. The spare area would normally contain ECC bytes for error detection and correction.

If you simply read the raw data plus ECC and then write it back, you will be making copies of any errors. You need to correct the raw data for errors, recompute the ECC, and write back the error-free data to your new IC.

I meant I bought a preprogrammed memory and copied it.

[SteveNielsen]

Re: Counterfeit NAND ICs?

I've done a little bit of shopping at AliExpress and so far got what I paid for (fingers crossed). I suppose it boils down to buyer beware as much as possible no matter what seller we're dealing with. I'm not sticking up for them, I know they're probably like all the other cut-throat outfits out there and can't 100% trust any of em. All sellers are potential crooks.

[fzabkar]

Re: Counterfeit NAND ICs?

I meant I bought a preprogrammed memory and copied it.

Sorry, now I understand. Still, it would be an interesting problem for those cases where you didn't have access to a known good image.

[lookimback]

Re: Counterfeit NAND ICs?

Sorry, now I understand. Still, it would be an interesting problem for those cases where you didn't have access to a known good image.

I want to learn how to fix them, I encounter them all the time. Well, more with SPI flash than NAND. It's all hex to me though. I've disassembled them with IDA Pro but don't know how to identify the correct starting point. I usually either buy a preprogrammed one from Shopjimmy or another reputable source. If nobody has it, I'll just buy a used board to get the binary and then just resell the board.

[lookimback]

Re: Counterfeit NAND ICs?

I've done a little bit of shopping at AliExpress and so far got what I paid for (fingers crossed). I suppose it boils down to buyer beware as much as possible no matter what seller we're dealing with. I'm not sticking up for them, I know they're probably like all the other cut-throat outfits out there and can't 100% trust any of em. All sellers are potential crooks.

I've placed 83 orders on AliExpress in two years. I've had maybe 5 which I didn't get what I ordered, but I've never had any trouble getting a refund. This is the first counterfeit item, and it's my fault that I didn't check them when they got here. I'd say I'm pretty comfortable ordering from there.

[fzabkar]

Re: Counterfeit NAND ICs?

This is a good tutorial on ECC and others:

https://cdn.badcaps-static.com/pdfs/...e50c04ce1a.pdf

Some cheap gear, too.

[lookimback]

Re: Counterfeit NAND ICs?

Off topic, but I've often wondered if I could mod my LG, which has DLNA, to make it have wired internet access. Seems like it should be possible for someone that knows how to program.

[lookimback]

Re: Counterfeit NAND ICs?

This is a good tutorial on ECC and others:

https://cdn.badcaps-static.com/pdfs/...e50c04ce1a.pdf

Some cheap gear, too.

Thanks. I'll definitely find this useful. Many times, the hardest part about learning is not knowing what to search for.

[Agent24]

Re: Counterfeit NAND ICs?

I've placed 83 orders on AliExpress in two years. I've had maybe 5 which I didn't get what I ordered, but I've never had any trouble getting a refund. This is the first counterfeit item, and it's my fault that I didn't check them when they got here. I'd say I'm pretty comfortable ordering from there.

That's good to know. I have always been wary of them, but they do seem to have more stuff than eBay and sometimes better prices. Sometimes it appears the only source for certain parts (though maybe those are true fakes, if nobody else has them!)

Do you pick sellers based on any feedback criteria etc?

[lookimback]

Re: Counterfeit NAND ICs?

That's good to know. I have always been wary of them, but they do seem to have more stuff than eBay and sometimes better prices. Sometimes it appears the only source for certain parts (though maybe those are true fakes, if nobody else has them!)

Do you pick sellers based on any feedback criteria etc?

I usually just pick the lowest price for the quantity I want. A lot of the MOSFETS and IGBTs are new board pulls. Usually they even have the same lot numbers. I'm assuming they must dismantle unused inventory. When ordering ICs, I usually don't go for the lowest price because they are usually loose, and then you end up having to straighten pins. I try to get ones which are in the original tape. The company is actually in the US, and in my experience, they handle disputes just like eBay. In fact, they're actually better because they'll accept video evidence. eBay won't accept any evidence but will go with "he said, she said."

[diif]

Re: Counterfeit NAND ICs?

I've had a couple of things wrong from Aliexpress, the wrong micro USB connectors and some FETs that didn't turn up. Not bad from about 100 orders and the correct connectors were sent allowing me to keep the old ones and the missing FETs were refunded.

A lot of sellers on ebay are just reselling Aliexpress sourced parts as they use the same stock photo.

[lookimback]

Re: Counterfeit NAND ICs?

A lot of sellers on ebay are just reselling Aliexpress sourced parts as they use the same stock photo.

Most that I've seen on eBay are also from China so maybe they're the same seller just taking advantage of a second marketplace.