Galaxy S3 I9300
Install Android 4.2.1 Jelly Bean on Galaxy S3 I9300 with CyanogenMod 10.1 ROM

Galaxy S3 I9300 users can now enjoy the latest Jelly Bean software with due release of Android 4.2.1 based CyanogenMod 10.1 (CM10.1) ROM.

CM10.1 ROM is known for its highly customised build with a plethora of exciting new features onboard. Some of its notable features include multi-user support, gesture typing, new quick settings option, lock-screen widget, photo sphere, enhanced Google Now, new day dream feature and miracast display.

The CyanogenMod 10.1 custom ROM is still an experimental build and may harbour a few untested bugs and broken features, which will be fixed in the upcoming updates. Despite the flaws, the custom ROM offers a high degree of customisation that stock ROM lacks.

Key Points to Note

  • The CM10.1 ROM and the instructions provided in this guide are applicable to the international version Galaxy S3 I9300 model only and will not work on other versions. Verify your device's model number by navigating to Settings > About Phone.
  • IBTimes UK advises users to back up apps, important data and settings to avoid risk of data loss while flashing the CM10.1 Jelly Bean ROM on your Galaxy S3 I9300.
  • Verify that your phone's battery has at least 80 percent charge to prevent unexpected device shutdown (due to battery drain) while installing the Android 4.2.1 Jelly Bean update on the Galaxy S3.
  • Make sure that the correct USB drivers are installed for your Galaxy S3 on the computer. Download Galaxy S3 USB drivers.
  • Enable USB debugging mode on your phone by navigating to Settings > Application > Development in order to ensure proper connectivity with the computer.
  • Ensure that your phone is rooted with ClockworkMod Recovery (CWM) installed on it.
  • 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 using the CM10.1 based Android 4.2.1 Jelly Bean update. Users are advised to proceed at their own risk.


Download CM10.1 Android 4.2.1 Jelly Bean ROM for Galaxy S3 I9300

Download Google Apps

How to Install Android 4.2.1 Jelly Bean on Galaxy S3 I9300 with CyanogenMod 10.1

1. Connect your phone to the computer with the original USB cable.

2. Copy downloaded ROM and Google Apps zip files to the root folder of the phone's SD card. Important: Do not extract any files.

3. Disconnect USB cable from the computer and then switch off your phone.

4. Boot the phone into recovery mode. To do so, press and hold Volume Up, Home and Power buttons together until the screen flashes. Then release all of them.[use volume buttons to scroll and Power button to select].

5. Take a Nandroid backup of your current ROM that you can restore later if something goes wrong with the new ROM. To do a backup, choose Backup and Restore and then hit Backup again. Return to main recovery menu once backup is done.

6. Next you need to do a full-data wipe. To do so, click wipe data/factory reset, then choose Yes on next screen to confirm. Wait for a few minutes until the data wipe process completes.

7. Choose install zip from sdcard and then hit choose zip from sdcard. Now, locate the CM10.1 ROM zip file that you copied to your phone earlier in Step 2 and select it by tapping Power button. Confirm the installation by clicking Yes on next screen and the ROM installation will begin.

8. After the ROM is installed, repeat step 7 and choose the GApps zip file instead of ROM zip to install the Google apps package.

9. Once Google Apps is installed, return to the main recovery menu. Now, choose Reboot System Now to reboot the phone into CM10.1 based Android 4.2.1 Jelly Bean ROM. The first boot may take about 5 minutes to complete, so leave it alone.

10. Returning to Previous ROM: To restore your previous ROM, boot into recovery, choose backup and restore then restore your previous ROM by selecting it from the list.

CM10.1 custom ROM based Android 4.2.1 Jelly Bean ROM is now installed and running on your Samsung Galaxy S3 I9300

[Source: Android Jinn]