Android Jelly Bean
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Nexus 7 received the official Android 4.2.1 OTA update based on stock firmware, as well as the stock rooted and de-odexed custom ROM a few days ago. Now, Android 4.2.1 CleanROM custom firmware joins the list and paves the way for a flurry of custom ROM Jelly Bean updates in the making.

CleanROM is reportedly designed to be simple, fast and free from bloatware or useless apps. The ROM also features superior battery life and enhanced performance, and adds a plethora of Android apps from Google Play Store.

Key Points to Note

    • The CleanROM Jelly Bean firmware and the instructions provided in this guide are applicable for the Nexus 7 device only and will not work with any other model or device. Verify your device's model number by navigating to Settings > About Phone.
    • IBTimes UK advises users to backup apps, important data and settings to avoid data loss while flashing the Android 4.2.1 CleanROM custom firmware on their Nexus 7 tablet.
    • The instructions provided in this guide are meant for reference purpose only and do not cover any warranty claims involving device damage or issues arising out of installing the Android 4.2.1 Jelly Bean firmware. Users are advised to proceed at their own risk.


    • Enable USB debugging mode by navigating to Settings > Developer options (the option may be hidden if you are running Android 4.2)

NOTE: If you are already running Android 4.2 on your Nexus device, then go to Settings > About Phone. Then scroll down to the bottom to locate the Build Number. Tap the Build Number about seven times (right after the third tap you will see a dialogue box saying you are only four steps away from being a developer. Continue tapping on it four more times). Now, you can access Developer options under Settings.

    • Verify that your tablet battery has at least 85 percent charge to prevent unexpected device shutdown (due to battery drain) while flashing the CleanROM custom firmware.
    • Ensure that your Nexus tablet is rooted with ClockworkMod Recovery (CWM) preinstalled on it, before proceeding with the ROM installation steps.

How to Install CleanROM Android 4.2.1 Jelly Bean on Nexus 7

Step 1 - Download CleanROM Android 4.2.1 Jelly Bean for Nexus 7 on your computer.

Step 2 - Connect and mount your Nexus 7 USB mass storage on your computer with the USB cable.

Step 3 - Copy the Android 4.2.1 ROM zip file to the desired folder on your tablet.

Step 4 - Power off your Nexus tablet. Now,press and hold the Volume Up, Volume Down and Power buttons together until the tablet boots into Bootloader Mode.

Step 6 - Follow the onscreen navigational instructions. Select Bootloader and progress into Recovery Mode.

Step 7 - In CWM Recovery, perform full data wipe first. Then browse to Flash zip from SD card option and tap the Power button to select it.

Step 8 - Hit the Power button again and click Choose zip from sdcard.

Step 9 - Now, use volume keys to navigate to Android 4.2.1 ROM zip file and select it by tapping the Power button. Confirm the ROM installation on next screen and the installation procedure will begin.

Step 10 - Once the ROM is installed, hit Go Back and reboot the phone by tapping Reboot System Now in the recovery menu. The phone will reboot and the first boot might take about 5 minutes to complete. So, leave it alone.

Your Nexus 7 is now successfully updated to Android 4.2.1 Jelly Bean firmware. Go to Settings > About Tablet to verify the firmware version installed.

[Source: Team Android]