After upgrading the Nexus S to Android version 4.1.2, Google stopped further Jelly Bean update for the handset. There is no official support for Android 4.2 for Nexus S. However, the device can now be updated to the latest Android 4.3, although not officially but unofficially.

Nexus S
Unofficial builds of CyanogenMod 10.2 are available for Nexus S I9020.

XDA member, noloukos has shared unofficial CyanogenMod 10.2 builds, featuring Android 4.3, for the Nexus S. Most of the features are working fine in this port except a few such as SuperSU and also the slider shortcuts cannot be changed in lock screen. Head over to the development thread to know more about the custom release.

Nexus S users, who wish to install Android 4.3 on their handsets using CM10.2 unofficial builds, may follow our step-by-step guide (Courtesy of Team Android).

It should be noted that since this is an experimental build, the Android device is likely to encounter with FC errors, boot loops, several other bug issues with the installation of the custom ROM. To fix this, users will have to reinstall stock firmware or any other stable version of custom build.

IBTimes UK reminds its readers that it will not be held liable for any damage to the device. Users are also advised to verify that their handsets meet following requirements.

Pre-requisites

1) Install USB Drivers for Nexus S to transfer files between the Android device and computer.

2) Enable USB Debugging Mode on phone to connect it with the computer and use Android SDK with it. [Press Menu>> Settings>> Applications. From there navigate and click on Development option and check USB Debugging Mode.]

3) As the tutorial is likely wipe all data of the phone, create a backup. If the device is having any custom recoveries such as ClockworkMod/TWRP already installed, then backup data using the recovery.

4) The Nexus S should have above 80% battery charge.

5) The phone should be rooted and have ClockworkMod (CWM) recovery installed.

6) The unofficial builds of CyanogenMod 10.2 only with Nexus S I9020. As installing this on any incorrect variant is likely to brick the device, verify the model number of Nexus device by navigating to Settings>> About phone>> Model number.

7) After flashing the ROM if the device gets stuck on Booting animation or experience boot loop then perform wipe cache partition and wipe dalvik cache five more times before rebooting the device.

8) Users are advised to give about five to 10 minutes to the ROM after the device boots up first time to settle everything for a better using experience.

Steps to install Android 4.3 Jelly Bean on Nexus S I9020 with CM10.2 unofficial build

Step-1: Download CM10.2 Android 4.3 Jelly Bean ROM for Nexus S to computer

File name: cm-10.2-20130814-UNOFFICIAL-crespo.zip [Alternative link]

Step-2: Download Google Apps

Step-3: Connect and mount the Nexus S USB memory on the computer using USB cable. Then copy the downloaded zip files to the SD card of the phone. Ensure that the files are in the SD card root, not in any folder. Also, do not extract any file

Step-4: Unplug the USB cable from the phone and switch it off

Step-5: Boot the Nexus S in the Bootloader Mode. To do so turn on the phone while pressing and holding Volume Up, Volume Down and Power buttons together

Step-6: Follow the navigation instructions on screen. Select BOOTLOADER and then go to RECOVERY

Note: In recovery mode, use the Volume keys to navigate between the options and Power button to select the desired option.

Step-7: In the recovery mode, perform a Nandroid backup of the existing ROM that can be restored later if the new ROM does not work or in case users wish to go back to the previous ROM. To perform Nandroid backup, select Backup and Restore then on the next screen select Backup again. Go back to the main recovery menu once the backup is completed

Step-8: Now perform data wiping task to eliminate clash between the new ROM and the previous ROM. Select wipe data/factory reset then select Yes on the next screen to confirm the action. Wait for some time until the wiping process is done and return to the CWM recovery menu. Now perform a cache wipe by selecting wipe cache partition.

Now this is optional but it is recommended to perform a wipe of dalvik cache to boot loops and any other errors. From CWM recovery, go to advanced option and then select wipe dalvik cache

Step-9: Return to the main recovery menu and select install zip from sdcard then select choose zip from sdcard. Navigate to the CM10.2 Android 4.3 ROM zip which was earlier copied to the SD card of the phone. Press the Power button to select it and confirm installation on the next screen. The ROM installation should begin now

Step-10: Once the ROM is installed, repeat the above step but now choose Google Apps to install same

Step-11: When the installation process is completed, go to +++++Go Back +++++ and reboot the phone by selecting reboot system now from the recovery menu. The device will now boot up into the customised CM10.2 firmware and it would take about five minutes to boot for first time

Note: To go back to the previous ROM, boot the phone into recovery, select Backup and Restore then restore the ROM by selecting it from the list.

CM10.2 unofficial build featuring Android 4.3 should be now installed and running on the Nexus S. To verify the new software version of the Nexus device, head over to Settings>> About phone.