I have a china tablet named Quest. I have accidentally repeated pattern lock more than 5 times. Now I have also forgotten the email address.

So for a factory-reset of my tablet I simply booted it into recovery mode. But it shows an Android bot lying with red exclamation mark. After a spending hours I found a shortcut i.e, vol + and power to access recovery menu. But my tablet doesn't go to recovery menu even when I pressed the keys.

So I simply connected my tablet to my pc via USB and installed drivers. In adb command prompt I typed adb devices. Now my tablet is listed as 20110301 recovery. I can simply use only adb pull, adb push, and reboot commands. But I cant access adb shell to unlock my tablet: it simply says exec '/system/bin/sh' failed: No such file or directory (2).

What can I do?

  • Have you checked with Cannot unlock tablet as have no internet connection? Many ways are listed up there, maybe one of them proves helpful for your situation as well.
    – Izzy
    Nov 1 '13 at 12:38
  • Thanks for your reply!!!But it does'nt solves the problem.Because they are also telling to use adb shell to unlock the tablet.But i can't even access adb shell .What to do?.Other methods does'nt works.
    – ShihabSoft
    Nov 1 '13 at 13:16
  • You've "forgotten the email address"? Have you ever used Google Play Store on a PC to install apps? If you're failing to factory reset then your only option (as far as I'm aware) is to use the email address. Nov 1 '13 at 13:25
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    If you tried all methods mentioned there, I'm out of ideas, sorry. Except of trying fastboot mode and use fastboot -w to wipe all userdata and cache (which basically is the same as a factory-reset).
    – Izzy
    Nov 1 '13 at 13:26
  • My tablet doesnt support fastboot mode.when i started into recovery mode it shows only android bot lying down with red traiangle and cant get recovery menu even after pressed power then press volume up.What to do ?Is there anyone in the universe to help me.Anyway Thanks!!!
    – ShihabSoft
    Nov 1 '13 at 18:55

You have a stock recovery. Try to boot to fastboot, using ADB: Apply this command in ADB while in recovery: adb reboot-bootloader, or: adb reboot bootloader. Try each one, if the first works, good. Check if the device is visible by fastboot devices. If it outputs nothing, try the other command. It should work now.

Now you have to flash the recovery using fastboot flashing abilities. After that, try again.

  • I'm in the same situation and I tried to put the device into fastboot without success. Do you have any other ideas?
    – Vincent
    Jun 4 '14 at 2:17

On stock recveries the adb utility only registers that the device is connected when you invoke the sideload utility which gives an error when you try applying adb shell or any other thing...it only accepts push commands to the device. adb also works when your phone is on which is a problem when you have boot issues and can only get to recovery.

Best Case Scenario:


1.Flash a Custom recovery via ODIN: the stock will prevent certain commands; TWRP or CWM are the Industries (Root) finest and give a provision to initialise the sideload utility or even better yet, Backup to an external SD Card. Press


to get to recovery:voila, your adb commands will work as required not to mention factory resets and wipes,


I Have the same problem with etech et-7008b tablet, the USB DEBUGGING is off before they made made too many pattern mistakes. My advice is make sure USB debugging option is checked/turned on before making any security password on your devices but it would be easier to unlock for those stolen or lost devices.


If you wipe the user data. That's a factory reset.

fastboot -w

You can boot a custom recovery and root it from that recovery also. Just fastboot boot recoveryname.img And flash root package and su and superuser.apk If it doesn't work its safe Cuz it didn't flash it just booted it. Cuz it will let you boot a recovery.IMG on the phone and not flash anything .try that

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