Downgrading Android tablets from Nougat back to Marshmallow is possible on your own. Below are some steps to manually downgrade your Android tablet featuring Nougat to Marshmallow. However, before you follow these steps, back up the important device data to a PC or a cloud account so that you can access the same in the future. Just like upgrading, even downgrading the Android tablets from Nougat back to Marshmallow would erase all the content in the Android device so backup is a must.
First up, you need to download and install the Android SDK Tool having .exe file extension from the Google’s developer site to the PC. Post download, install the SDK Tools to C:android-sdk in the PC and then launch download from the Start Menu once installation of SDK Tools completes. After that, open SDK Manager, check Android SDK Platform-tools as well as Google USB Driver, and uncheck other options. Then, click on Install 2 Packages and then check Accept License > Install when the SDK Manager prompts.
Secondly, you need to download the Android 6.0 Marshmallow factory image directly through one of the Google Android developer sites. After download, simply unzip the downloaded Marshmallow ISO file in the same directory where you installed SDK tools.
Thirdly, enable USB Debugging in the Android tablet so that you can connect the same to the PC through USB cable.
Steps for Flashing Marshmallow Factory Image
- Open the command prompt, key in cdandroid-sdkplatform-tools and then hit Enter button in your PC.
- Then, key in adb reboot bootloader and again hit the Enter
- After that, key in fastboot oem unlock to unlock the Android tablet (This is where the data get erased).
- Key in flash-all to install the bootloader, baseband firmware as well as Android Marshmallow
This process will last for minutes so don’t shut down your Android tablet. Once the flashing finishes, Android would reboot automatically and thereby downgrade Nougat 7.0 to Marshmallow 6.0. If you lose data after the downgrade, then you would have to download and install free data recovery software from Google Play Store and re-partition the Android tablet you own.