Looking for Help Rooting Coby MID9740

Discussion in 'Coby Generation 3' started by neumanb, Nov 20, 2012.

  1. neumanb
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    neumanb Junior Member

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    I just recently bought the new 9740-8 and would like to root it to gain access to the play store and other Google apps. I have not been successful in finding instructions or ROM's for this specific model. Any help would be greatly appreciated. Thanks!
  2. vampirefo.
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    vampirefo. Senior Member Developer

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    This version of Coby is in high demand, once you root this tablet make a dump and upload it, if you don't, you will be sorry so many users simply wont make a backup and upload it, then when trouble happens it's extremely hard repairing their tablet.

    The root method for any of the coby's 8042, 7042, 9042, 9742, 1042, will work on this tablet. you need to get adb installed and working first, then follow instruction on dumping your tablet upload your dump and let one of the advanced members look it over and insure you have all 4 parts of the backup, the system being the most important, before you modify your tablet.
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  3. jmblouin
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    jmblouin Junior Member

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    Take your time...

    Are you a windows, mac, linux user?

    Have you ever used adb before?

    If you use windows use this from Traveller CobyADB.zip

    Follow this thread, read it and read it three or four more times http://www.androidtablets.net/forum...ead-first-development-index-root-utility.html
    Rooting and Dump Utility for Windows (updated 11/21/12):
    Traveller1701 just updated the dump utility to replace busybox so that you can get a system.tgz dump (This was missing from my dump and I need it badly....)

    This thread tells you what files you should have in your dump http://www.androidtablets.net/forum...ment/49945-busybox-do-you-have-right-one.html
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  4. Diegom
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    Diegom Junior Member

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    Hi!

    I recently got a Coby 9740 and I followed the threads above to root it (thanks jmblouin, vampirefo and traveller for the great help!).

    Using ADB (Win 7) I also create a system dump, apparently successfully. The dump, including the system.tgz, can be found here:
    Coby 9740 Dump.zip

    (I had installed a couple of apps --opera, games-, so it may no be completely stock. Sorry about that)

    I did run into a problem though: I don't seem to be able to have root access from adb. when I try, for instance, to
    mount -o remount,rw /system
    I get
    mount: permission denied <are you root?>

    I am now interested in installing Gapps. should I worry about the root issue first?
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  5. vampirefo.
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    vampirefo. Senior Member Developer

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    adb shell
    su
    mount -o remount,rw /system
  6. vampirefo.
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    vampirefo. Senior Member Developer

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    Can you recheck your system.tgz it's corrupt.

    if you can

    adb shell

    su

    busybox tar -cvzf /sdcard/dump/9740_system.tgz /system
  7. jmblouin
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    jmblouin Junior Member

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    The system was currupt for me as well. Diegom can you try reading the system.tgz with either winrar or 7zip prior to upload to see if the file is currupted before you uploaded it?

    Also follow what vampirefo. said.
  8. Diegom
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    Diegom Junior Member

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    I did as suggested

    after a long string of files, the command ended in
    tar: error exit delayed from previous errors

    the last line before that was
    system/xbin/su

    I have no problem opening the system.tgz with winrar.
    In any case, I uploaded it again, on its own. this is the link
    system.tgz

    Guys, would you direct me to a thread with fool-proof guidance on how to isntal Gapps, preferably without installing a custom ROM? I keep getting lost in the forum. Thanks!

    let me know if there's any info from my tablet that me useful.
  9. jmblouin
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    jmblouin Junior Member

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    I am afraid that your system.tgz is currupt. When I attempted to recover it all I can get is the system/app folder. All the apk and odex files seem to be in tact in there. For comparison reasons download this and compare that system.tgz to your own (DO NOT USE THIS FILE FOR ANY OTHER PURPOSE OTHER THAN TO COMPARE YOUR FILES WITH).
    MID9742 Dump v3.rar
    Lets make sure we get this resolved before we install anything (cwm-recovery which you should not install until we get a version meant for our tablets I'm using cwm-for 9742 but it will not boot to recovery using the 2 fingure method only using adb shell, su, reboot-recovery, gapps). Believe me you will be happy you waited.

    In adb click on the top left small icon of cmd and go under edit and click mark. than drag your mouse over all the data there. Once you have all your data selected (should be white) right click your mouse and than go the forum and post a reply of all that data here by right clicking paste. Than we can see everything you can.

    edit: For some reason superuser.apk must not of pushed when rooting (at least I dont see it when I look over your faulty dump). When you look under applications on your tablet do you see an app called superuser?

    In adb after adb shell you get root access by typing su (kind of like logging into an administrative account in windows versus a guest.)
    Last edited: Nov 25, 2012
  10. Diegom
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    Diegom Junior Member

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    Thanks jmblouin.

    I downloaded your dump, and indeed things were very different than on my own, which only had app folder under system and nothing else. I have now created another system dump which does contain all the bin, etc, .... folders. you may find it here (please use this entire dump and do not mix the img files with the previous one, since in the meantime I did a factory reset to the tablet, so things may be a bit different between the two)
    9740_dump.rar

    Yes, I did have an superuser application. and the strange thing is that also even after my factory reset I still get a superuser app straight away (!!). Is it possible?

    let me know if this dump contains all the information you need. If not, I will try copying and pasting all the info I can get from adb (please be specfic about what info you need).

    I'll wait for your answer before trying anything else.
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  11. vampirefo.
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    vampirefo. Senior Member Developer

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    This dump seems fine, My Linux found no corruption in the tar.
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  12. jmblouin
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    jmblouin Junior Member

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    What would it take to use this dump as a reference to get cwm-recovery fully working for 9740-8 devices?

    If we get a version of cwm-recovery for our devices than you can make a nandroid backup, flash gapps to your device and I can try making a build.prop based off of your dump and travellers tweaks. This is in my opinion easier. Otherwise we could manually push gapps with adb. I am not familiar on how to do it this way so you would need assistant from vampirefo. for this one.
  13. vampirefo.
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    vampirefo. Senior Member Developer

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    My guess the recovery is the same as 8042 and 9742. I see no difference in the dump.

    What problems are you having with the 9742 recovery?
  14. jmblouin
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    jmblouin Junior Member

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    I cannot access the internal sdcard with this version or boot into recovery with the physical buttons.

    The devices might be setup like a 7042 and 9042. I guess I could try to the recovery from 9042 and see if it works.
    Last edited: Nov 25, 2012
  15. vampirefo.
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    vampirefo. Senior Member Developer

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    Here you go.

    9740_v6.0.1.1_recovery.zip
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  16. jmblouin
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    jmblouin Junior Member

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    How to get these files to your device:

    unzip the file to where you have adb at

    adb push install-recovery.sh /data/local/tmp/install-recovery.sh

    adb push CW_recovery.img /data/local/tmp/CW_recovery.img

    adb shell

    su

    busybox mount -o remount,rw /system

    exit

    exit

    adb push reboot-recovery /system/bin/reboot-recovery

    adb shell

    su

    chmod 755 /system/bin/reboot-recovery

    chmod 777 /data/local/tmp/install-recovery.sh

    /data/local/tmp/install-recovery.sh

    /system/bin/reboot-recovery

    your device should now reboot into cwm-recovery.

    to navigate use the volume up and down, power to select, back to go back

    navigate to backup and restore and perform a backup

    reboot the tablet.

    now go to this link and download gapps and put it onto your sd card

    20120429

    open up adb

    adb shell

    su

    reboot-recovery

    You should now be back into cwm-recovery.

    Navigate to install zip from sdcard, choose zip from sdcard and select your gapps zip and install it, now reboot your device once its finished. You should now have gapps, but you will be limited to the apps you can download until we get your build.prop updated to fool the market into thinking you have a compatible device.

    now go back to adb
    adb shell
    su
    reboot-recovery
    do another backup if everything is working right.
    Last edited: Nov 25, 2012
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  17. jmblouin
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    jmblouin Junior Member

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    vampirefo. If I wanted to modify the system.tgz to have usb debugging on could I do that through the build.prop and if so where and how?
  18. Diegom
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    Diegom Junior Member

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    guys, that worked like a charm!! everything is install and seems to be working fine. I got a fresh backup after install gapps.

    is it possible to get google play going?

    thanks so much in advance for your great help!
  19. vampirefo.
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    vampirefo. Senior Member Developer

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    persist.sys.usb.config=mass_storage,adb
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  20. jmblouin
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    jmblouin Junior Member

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    Do you see google play in your app drawer?

    If not backup to a backup prior to installing gapps, reboot to confirm that the tablet is still functional. Than go back to cwm-recovery flash the gapps zip once again, than go back and go to advance and click report error. Reboot the tablet. There should now be a file in your clockworkmod folder on your sd card called recovery.log. turn on usb storage and view that log file with wordpad and copy the data to the forum so that we can look at it.

    This is what I get when I attempt to flash gapps.
    I havent figured out a solution for this yet....

    If you are just talking about "device not compatible" message in google play, I havent had a chance to work on the build.prop yet since I am working on other issues with the tablet first.
    Last edited: Nov 28, 2012
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