USB FLASH drive repair

During the last years I repaired quite a lot of USB FLASH drives where the owners weren't able to read out the data anymore. Most of them were SanDisk Cruzer types. You can find a lot of complaints about failures online.




All of them had one thing in common: A hardware failure which was easy to repair.

First let's take a look at a common USB 2.0 thumb drive (or USB stick) design. There's not much components to see when they are naked.




The main part is the USB controller. In this case it is a USBest U165. Sometimes there is a hickup in the controller. There are utilities on the web which you can use to repair this. Have a look at this example or use Google to find software for your controller. But you will loose your data most likely. Also, that turned out not to be the problem on all the USB drives I repaired.


A closer look at the other side reveals this:




You can see the FLASH IC on the right side. That's where the data is stored. This could also fail and your data is lost forever. But you may check if all pins are soldered correctly and that there is no crack at one ore more pins.


But the part which was broken on ALL the sticks I got hand on during the past years was the crystal.




For those of you who are not familiar with crystals (which are used for clock generation, in this case for the USB controller): Usually they have a thin "glass" inside which oscillates. Here is a picture by Chribble76 taken from Wikipedia (Public Domain).




As you can see, this structure can easily break if you throw around your thumb drive. If it cracks or a small piece breaks off, it will not have its specified frequency anymore and thus the USB controller wil not work (properly). After frequency measurements with a plugged in USB stick, I noticed that the XTAL frequency was not 12MHz, but close to 11 MHz. This caused the error that the stick was constantly dis- and then reappearing in the operating system within seconds. With this behaviour you do not even have the slightest chance of using data recovery tools or oftware to repair your controller.

So what I did to repair all the USB FLASH drives was simply to desolder the broken XTAL and replacing it with a good one. If your stick breaks at a weekend, you can use a crystal taken from a good USB drive.


Often there are more than one solder pads to accomodate different XTAL packages.


But it should be easy to find the right pads.

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  1. Lupin says:

    Did you find out which crystal types would break most often?

    I can imagine that can-type crystals are most fragile and prone to failure due to mechanical stress.

    Did you ever have a broken surface mounted crystal?

    I actually saw a TV show where they also said the crystal was the most susceptible part of an USB stick. But there they said it has to resonate at 12 Hz :-)

  2. t0bY! says:

    Hi Lupin,

    all of the USB drives I repaired with the above error had the tiny can type crystals. So I cannot speak for other XTAL types in conjunction with USB-Sticks. But I know from my work that they should be the ones most susceptible to mechanical damage. If the glue comes lose, also their thin leads easily break.
    12 Hz is funny :) Do you remember which TV show they talked about this?

  3. EDV-Dompteur says:

    Sehr gut erklärt und mit prima Bildern versehen!

    Deckt sich mit meiner Erfahrung, wobei ich allerdings auch schon andere Fälle auf dem Tisch hatte.

    Ich war mal so frei, eines der obigen Bilder zu guttenbergen und (unter Angabe der Quelle) den Beitrag bei mir zu verlinken:

    http://edv-dompteur.de/forum/index.php?page=Thread&postID=623#post623
    (Obiger Link wird hier auf zwei Zeilen umgebrochen. Wie kann man das verhindern? Der URL-BBcode funzt hier nicht.)

    Falls gegen die Bildeinbindung Einwände bestehen sollten, bitte ich um Nachricht, dann entferne ich die Sachen umgehend wieder.

    Ergänzend kenne ich noch den bei manchen Sticks wirksamen Trick, einen oder beide Ziekapazitäten beim Quarz zu entfernen, bzw. zu verändern.

  4. t0bY! says:

    Hallo EDV-Dompteur,

    wer lieb fragt und die Quelle angibt darf auch gerne das Bild benutzen!
    Den BBCode musste ich leider wegen zu hohem SPAM-Aufkommen irgendwan mal abschalten. Ich kann aber mal schauen ob ich Deine URL nachträglich noch als Link abändern kann.

  5. JaWi says:

    Just revived a DoA 64GB drive by replacing its crystal, thanks for the hint t0bY!

  6. t0bY! says:

    You are welcome, glad it works again!

  7. David Peters says:

    Just revived a Teacher's Flash Drive with tons of exams and teching stuff. She is very relieved.

  8. Ofir says:

    hi , would this also work for USB 3.0 ?
    i have a faulty A DATA 32GB usb stick which i opened up but i cant find anything that looks like the crystal in the picture.

  9. t0bY! says:

    Hi Ofir,

    yes, this could also work with a USB 3.0 stick. If you cannot find a crystal, you can send me a picture of the opened stick and I can point you to it. My contact data is listed here in the Blog under "about".

  10. Ken says:

    COMMENT_DELETED

  11. t0bY! says:

    Ken,

    yes, the root cause of this error could be a defective crystal. Do you know anyone who is more experienced in electronics? You could show this post to them and ask for help on this.

    Regards,
    t0bY!

  12. james says:

    Great article. Another USB memory stick revived. Thank you.

  13. hans swinkels says:

    i have a non-working usb stick and the crystal is becoming very hot. Is this caused by the crystal or another cause?

  14. t0bY! says:

    Hans,

    hard to say if the crystal is not properly working. Do you have a frequency counter or scope so that you can measure its frequency? If not you may want to replace it with a good one and see if ste stick comes to life again...

  15. Matt says:

    hello, I have a USB thumb drive I need to recover. It just quite this week for no apparent reason. However after taking it apart I do not find a crystal as shown in the pictures in the post. What to do?

  16. t0bY! says:

    Sorry to hear that, Matt.

    If you can, send a picture (preferably high resolution) of both sides of the thumb drive PCB. I then can point you to the location of the xtal. Do you have skills to solder a new one or do you know people who can assist you?


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