I bought a 1 TB Micro SD Card off of Amazon and got scammed. When I put it in the computer it looks like it's the right size. But if I reformat it or check the drive information with any kinda of developer tool I can see that 3/4ths of the space is "used" by nothing. Even right after a reformat. I zero'd out the card just incase but that did nothing (as I expected it wouldn't).

What I want to do now (and need steps to follow to do this) is to undo this ridiculous hack and restore this card to whatever size it was originally. It might be a silly 8G card... or maybe it will end up being a 250G one... who knows. But either way I want to try and restore it and see.

Right now whenever I put a large file on this SD card it corrupts all files because its trying to pretend to be larger than it is, and it's doing this by re-writing over the first few sectors over and over again.

So again, not trying to get the 1TB back... I know I was scammed and the memory just isn't there in the card. However, I still want something for my money so I am hoping I can turn this back into a lower sized card.


Please don't give me your opinion on whether this is a good use of my time or not, I can decide that for myself thank you. I am looking for steps to

  • Go into the SD card via the "correct" hardware (regardless of the efforts)
  • Update/change the microcontroller code in the device
  • Buy a piece of hardware that can help me to undo this

I stated above in my question (twice) that I am NOT trying to create space that doesn't exist. I just want to turn this back into the normal sized drive it was before-hand. If you care about the non-technical side (which clearly people are caring...) I am convinced this is a 64G SD drive and I could actually use that for some other project. That project... is learning how SD cards work.

  • What tools are you using to see the various sizes? If the card is reporting that it's 1TB, a partition editor should be able to create a 1TB, more or less, partition. It is possible that what you have is actually just a defective card, and you weren't actually scammed. I'd return it as defective. Jun 8, 2021 at 1:13
  • In general it's just a bad idea try fixing fake drives as often the components such as NAND used are poor quality. Sep 9 at 13:13

5 Answers 5


You can try F3 - Fight Flash Fraud. It works best, more completely, in Linux.

It has a good track record / success rate but it's not guaranteed in all situations. Meaning: It won't detect the actual capacity in all situations and even it does it may not be possible to recover it in some usable form, even temporary.

No SD or USB flash drive coming from this scams should be used for anything important.

If backups are a must in any situation for any files we can't afford to loose even more so in this case due to reliability issues. The typical source for this scams are very old and/or factory rejects (failed QC) that will totally fail much sooner than their known good counterparts.

  • I am convinced this is a 64G SD drive and I could actually use that for some other project No, it will be something between 1-4GB and even that capacity is unreliable. If it was a good 64GB it would be sold as such with zero effort. The specialized hardware and wrok hours needed to pull this scam wouldn't be profitable unless the scammers can source SD cards that cost cents per unit. Jun 8, 2021 at 13:31

Don't bother.

That's the advice from: https://flashchiptech.wordpress.com/2010/12/07/chip-genius-the-good-and-the-bad-about-this-software-in-identify-flash-memory-chips-and-repairing-fake-hacked-memory-how-useful-is-chipgenius/

which says, "Memory cards continue to be next to impossible to repair. Few succeed. You can’t open them. You will usually get the wrong VOD and PID information because of interference from the usb reader. Some people do succeed but there is no tried and true method as yet for everyone."

A bit earlier, the page notes, "It is possible to restore usb flash drives that have been hacked. MP3 MP4 and MP5 players too." And, "You need the right low level reformatting tool to succeed, use the wrong tool, you" lose it.

Lots more information on that web page is discussing your exact scenario.

  • 1
    Disclaimer: I don't claim expertise on this; I haven't used the software described. But since I very recently came across an article that addresses this exact question, I wanted to share the useful resource. I understand the potential of some details possibly being incorrect, and don't have further informed details/opinions to be adding at this time. Good luck.
    – TOOGAM
    Jun 8, 2021 at 1:15

The method the scammers use to make the drive report the fake size is not one which can be done, or reversed, using any regular software. They actually reprogram the microcontroller inside of the card.

These aren't designed to be user reprogrammable. Programming them usually involves either physically opening the unit and connecting a programming tool, or using a software or hardware tool which can reprogram it over the SD interface's pins, but the tool isn't a regular end-user tool and is specific to the type of controller.

Usually, however, the main side effect of the hack is that the drive just can't use any of the "space" beyond a certain point because that space doesn't exist. This is why the drives appear to work fine for a long time. So, you could theoretically create a filesystem that simply does not cover the whole drive. The usual formatting tools in Windows won't let you do this as they treat a portable drive as one big partition but third party or command line tools will. It would be relatively easy using a live Linux install.

You first need to find out the true size of the drive. This can be quite a bit more complicated than it would seem. You can write to the entire drive and it will appear to succeed, even if it hasn't written. Or, the writes may even loop back over and over, letting you even read back recent writes correctly.

There are plenty of tools made specifically to test for fake flash drives.

  • I don't run Windows, I run Linux only. I don't care about it being a "waste of time" I asked how to fix this. I want to know because its useful to me. Also, reprogramming microcontrollers is what I do at my job for a living... so... Do you have any advice on how to change the microcontroller code? If not I don't find this post helpful. Your opinion on making this change is unwarranted.
    – GoreDefex
    Jun 8, 2021 at 11:56
  • Your attitude is dreadful tbh. Sep 9 at 10:46

Sometimes creating a partition that spans only a part of the memory card may work, but it's not safe.

That's because the storage inside the card isn't accessible directly to the computer. The controller is maintaining an additional mapping of logical blocks (that computer sees) to physical blocks (that are actually there). This is necessary because rewriting, or even re-reading a block repeatedly, can cause it or its neighbors to degrade. The controller reallocates such blocks to an unused physical location and updates the mapping, so that logical blocks remain unchanged and the computer doesn't notice anything.

This mechanism is very reliable on a proper SD card, but with fake capacity cards the controller doesn't realize that these spare, supposedly unused locations actually overlap other locations that may be in use. Two logical sectors will correspond to a single physical one, breaking data consistency.

So all in all: You can try to leave the "fake" space unpartitioned, but don't trust this card ever.


My best luck to date has been in Linux, when I have had reasons to try and fix/change a memory device with wrong capacity listed. My device(s) have been formatted to be smaller than their actual capacity (I don't remember why anymore, I think it was a bad windows iso tool). But I think I have done it through windows disk partition manager. But it was the command line tool (diskpart?).

I haven't bought any "hacked" media, as I generally assume any "too good to be true" deals are. But diskpart/gparted should be able to make it "right". However you will lose any data on the drive when you do.

I do agree with others, a USB drive is NOT archival storage. It's a transfer media...


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