HDD GURU FORUMS

Hi Guys n Guru's,

I have a 32Gb SD Card that after a power outage whilst tansferring data now only appears as an unformatted 8mb partition. I have tried all the usual (and un usual) to attempt to reclaim or recover the missing partition, but to no avail. I have tried to remove the small 8mb partition using a variety of GUI and DOS based tools but this seems not to work either.

The card is un-branded, and i'm reading a lot of reports about "fake" cards having similar issues, is there any way, or utility I can use to determine this, or moreover, restore the missing portion of the drive?

This is a DR case.

Any suggestions would be welcomed..........

Many thanks,

Steve..

I guess, the first question would be where did you buy it?

Hi Steve,

It's not clear to me whether this is your card, or you're attempting DR for a customer... Since you don't mention a customer, I'll assume it's your card.

Well, scratchy has asked the same question I would have done I'd also add a question asking exactly what is marked on the card (e.g. serial number, location of manufacture etc)? These answers help to build up a picture of it being a likely fake or not. The fact you mention it is unbranded, yet is supposed to be a 32GB card (which should cost ££££), is not a good sign IMHO

Touchclarity wrote:I have a 32Gb SD Card

What testing was done of that card, before the "failure"? For example have you filled it (or nearly filled it) with data (photos or anything) and successfully read everything back and confirmed it existed on the card and was readable?

Touchclarity wrote:i'm reading a lot of reports about "fake" cards having similar issues

True.

Touchclarity wrote:is there any way, or utility I can use to determine this
[...]
This is a DR case.

Yes, there is software (inc at least one freeware utility) to identify the true card's capacity, but all such generic software (i.e. not specific to a controller chip on the card) is destructive to the data on the card. That's because they write known patterns on the card, which vary with the address (i.e. the test data is LBA-specific); then read back all addresses which were written and see what is actually there. So since this is a DR situation, you can't use that data-destructive approach.

A typical fake card (or USB stick etc.) would have its controller programmed to report a size of [big]GB, yet would only have [small]GB of actual physical NAND flash. Capacity testing software would then write [big]GB of LBA-specific data, and find they can only read back [small]GB of unique LBA-specific data from the card, and the fake is exposed (or sometimes the card fails completely when normally reserved areas of the flash are written during such a test - this can cause similar behaviour to what you are reporting).

Obviously the card can be opened to see if the flash is in a normal chip package, and the chip markings often [but not always] then confirm it is only [small]GB. Sometimes the chip marking appears to be [big]GB, but it is either very faulty, or has been re-marked, or has had its marking removed (which is another clue for a fake).

If this is a fake with only [small]GB of physical flash memory (where [small]GB < 32GB in this case), then the very best result would be that by accessing that flash directly, it might be possible to retrieve [small]GB of data using a NAND reader.

Good luck...

All the symptoms of a fake memory are present, to me.

To determine if the SD card is genuine, test it with H2testw:
http://www.heise.de/software/download/h2testw/50539

fzabkar wrote:To determine if the SD card is genuine, test it with H2testw

However in this specific situation, the OP must not use that utility, for the reason I explained above - that program writes to the card, and the OP wants to recover the data

Thanks for the correction.

ok, I ordered 2 32gb micro sd chips from china......they did read and hold 32 gigs of info, one day, while uploading to the chip, the power went off, now the chip only reads 8mb, windows wnats to format it, but wont or cant....I sent the chip to sandisk to see if it can be fixed, they wrote back that the chips had no serial numbers on the bach, therefore was a fake chip. I tried to use the program H2testw ,but without the chip being formatted, the program wont work....any suggestions?.......yours truely....Screwed...lol