Nexus 7 is among the premium Android devices to receive the Android 4.2.1 incremental update that aims to fix the bugs in previous iterations. Although Google has been rolling out the Jelly Bean updates in stages, the current Nexus devices - Nexus 4, Nexus 10, Nexus 7 and Galaxy Nexus - have grabbed the Android 4.2.1 update either through OTA or manual download portals of the Android developer community.
With due credit to XDA developer scrosler, users who missed the twin-opportunities can now download and install the pre-rooted and De-Odexed version of Android 4.2.1 ROM. The incremental Jelly Bean update also fixes a couple of pesky bugs including December bug, as well as Bluetooth audio issues that were recently reported. Measuring just 1.1 MB in size, the new update (based on JOP40D firmware) provides a convenient platform for users to apply official OTA update without having to root their device again later.
Disclaimer: The instructions provided in this guide are meant for reference purpose only and do not support any warranty claims involving device damage or issues arising out of using the Android 4.2.1 Jelly Bean OTA update. Users are advised to proceed at their own risk.
- The JOP40D ROM and the instructions provided in this guide are compatible with the Google Nexus 7 model only and will not work with any other 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 risk of data loss while installing the Android 4.2.1 Jelly Bean OTA update.
- Ensure that your device's bootloader is unlocked and either ClockworkMod Recovery (CWM) or TWRP custom recovery is preinstalled on it.
- Download the latest version of Stock Rooted Android 4.2.1 ROM for Nexus 7 from here.
How to Update Nexus 7 to Stock Rooted and De-odexed Android 4.2.1 Jelly Bean ROM
- Connect your Nexus 7 to the computer with the USB cable and copy the downloaded ROM zip file to the tablet.
- Now, power off the tablet and boot into Recovery Mode. To do so, press and hold Volume Up, Volume Down and Power buttons together until a green Android Robot with the letters Start (at the top right) appears on the screen.
- Double tap the volume key to highlight the Recovery Mode option, and then hit the Power button to select it and boot into TWRP.
- Take a full Nandroid Backup of the current ROM, so that it can be restored back if something goes wrong with the new ROM. To do a backup, click Backup (ensure that System, Data and Boot boxes are checked) and then slide the blue circle button at the bottom to the right to begin the backup process.
- Once backup is done, return to the main menu by tapping the home button at the bottom left of the screen.
- In main menu, click Wipe, then choose Factory Reset and confirm the action on next screen. Then tap Cache from the Wipe menu and confirm the action. Finally, click Dalvik Cache and confirm the action on next screen.
- Once the data wipe process completes, hit Go Back to return to the main menu.
- Click Install and browse to Stock Rooted - JOP40D - De-odex.zip file that you copied to your tablet earlier and select it. Slide the blue circle icon on next screen to begin the ROM installation.
- Wait until the installation completes and then click Reboot button. Finally, tap System to reboot your Nexus 7 into the newly installed OS. The first boot after ROM update may be time-consuming. So, leave it alone.
Stock Rooted Android 4.2.1 JOP40D ROM is now successfully installed on your Nexus 7 tablet. Go to Settings > About Tablet to verify the firmware version installed.
[Source: The Android Soul]