Recover Tablet Coby Kyros 7024 - Radical method

Discussion in 'Coby Generation 2 Technical' started by rancho, Nov 4, 2011.

  1. rancho
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    rancho Junior Member

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    Location:
    Brazil
    Tablet / Device:
    Kyros 7024
    After a lot of work, reading many Web blogs, I could recover my Kyros who had already given up for lost.
    First I would like to thank all the people who posted articles on the Web, because it was with this knowledge that I could come up with this method.
    I will not thank anyone in particular, it would be unfair to others.

    It is a way to recover the Kyros when it did not power on anymore.

    After testing some ROMs changing, my Kyros had the image recovery damaged, then to attempt to override a custom ROM to enable the buttons and the camera (most of the ROMs do not have drivers for this device) the Tablet was not starting by the OS installed on the NAND and also without recovery function.
    Pressing the power button lights lit, but if I release the button it turns off. If I kept the "power" button pressed for a while, it also turns off, it is the command to the hardware forces a power off.
    I'm no expert, to be honest I’m just a big curious, but my conclusion is that this tablet has an internal NAND memory, another internal memory in the form of microSD and an external memory microSD well.

    The NAND memory would stay with the main part of the OS, and the instructions to locate the remaining in internal memory microSD. The hardware of the tablet is setup to find the instructions on the NAND once it turns on.
    In my exchanges ROMs I have seriously damaged the contents of the NAND, making it impossible to boot.
    After trying several possibilities, methods of other tablets, remove battery, short pins of NAND, etc.. I found in SlateDroid a people who are making a dualboot on some tablets and one of the instructions used a mainborad Samsung, the same as Kyros 7024 - S5PV210.

    The thesis is that you can, by hardware changes, configure the tablet to find the OS on a different memory than the original, for example, the external memory.
    I figured that I could use this method to put a good ROM in external memory, so the tablet could boot it and run the installer.
    Before you continue, you will need some practice using a soldering iron. I recommend a soldering iron low power (15W) as the components and board are very delicate and in case of accident the chance of losing the device is quite large.

    Said that, let's go to the method:
    First, you need to open the tablet. There are no external screws, the cover is only attached, but as there are various locks it can be a little difficult at first. Do not force too much, because it can break down the parts that are all plastic. It is also not recommended to use anything made of metal as it may harm the device.
    I used an old credit card. I cut it in half and started the entry form the external memory slot. I pushed a bit to create a gap between the back cover. Then with the other half of the card would take turns leading the way enters the halves of the card.
    Be careful when removing the cover, because there are two speakers attached to it.
    Once opened, you will find the battery on right, complete board on left and the mainboard in the middle of the complete board.
    With the soldering iron, remove the battery.
    Attention, write down everything removed and it is important to keep the position of the wires (red, black, etc.), if the reverse when mounting ... "tchau."

    <see pictures on my personal site (Portuguese): http://www.amodio.com.br/main/Blog/tabid/104/EntryId/17/Tablet-Coby-Kyros-7024-A-ressureicao.aspx>

    On the mainboard, you will need to find the resistor that sets the processor to boot from NAND. It is located in the lower right corner of the board.
    <see pictures on my personal site (link above)>

    It is the only resistor in the middle column.
    <see pictures on my personal site (link above)>

    Be careful when removing it to avoid damaging the board. If you are really good with soldering skills you can put it back again.
    After removal of the resistor, solder back the battery, format a microSD to FAT32 and copy an adequate ROM installer to it. The Coby, on their website, already offers a version of the original ROM. if you want all functions working, I recommend it. Place the microSD on external slot.
    Try turn on the tablet in restore mode (center button + power). The tablet should power on, recognizing the OS from external memory and start the recovery.

    After the installer finished, the tablet should be functional again, even starting with the internal NAND.
    Then you will ask, but the resistor was not put back? No. The problem is that the tablet will not turn on if there is not a microSD on external slot. The memory does not need to have an operating system. When you call the function without recovery, the hardware starts to read the external microSD, but continue from the internal NAND (deduction).
    If this is enough for you, you can stop here.
    In my case it was not and I wanted to return to the original condition of the hardware.
    Unfortunately I had no ability to return the original resistor. It measures about 2mm and after several attempts and back pain began to realize that the board was suffering. I decided to investigate an alternative. Following the terminals for a place more accessible.
    I found a point at the top of the general board (not the mainboard). There exists a space that seems to be some other component that does not come in this model, possibly the GPS sensor.

    I get a common 1/8W resistor with 10Mohms and a piece of wire thinner than I thought. For the wire you can also take a flexible electrical cable, strip it, and pick apart few of the smaller filaments.
    On the terminal indicated above (possible GPS), count the pins from left to right, solder a wire on pin 1 and the other on pin 4. Connecting these wires use the resistor. After that I made &#8203;&#8203;a little drip silicone just to better fix of the components.
    <see pictures on my personal site (link above)>


    That is it! I hope to help someone.

    I'm currently using a Gingerbread version that is much more stable than its own original ROM (Froyo) of Coby. It’s name is PhoenixMod, the problem is that the camera and side buttons isn’t working, but I preferred that.
    Does anyone know if, once we have root access, you can install and configure a driver for the camera for example, without a full system reinstallation?


    Good luck,
    Alexandre Amodio.

    Solo Deo Gloria!
  2. flxrms
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    flxrms Junior Member

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    epad
    Thanks for the info but I believe that most blog out there got the information from this Colby sub-forum. Phoenix mod is already outdated you should try the new rom's at the development section.

    Camera don't have a driver, it must be initialize at bootup. Using phoenixmod uboot bin is the main reason its not working. There's no way that your camera will work again if you don't use the original uboot.bin.

    Please read the 7024 all you need to know thread.

    Sent from my typewriter.
    Last edited: Nov 4, 2011
  3. lfom
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    lfom Junior Member

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    Nice tutorial and info! Most if this has been documented already in the thread below:
    http://www.androidtablets.net/forum...3007-project-reviving-hard-bricked-kyros.html

    Normally it's not necessary to even set smdkv210 board to boot from SD changing the resistors, many have reported that only by using a properly made microSD in the external slot it's possible to start tablet and flash a new ROM. If it doesn't work, then opening the tablet and shorting NAND pins 7 & 8 as explained in the thread above is enough to revive a bricked tablet. ;)

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