Install Unofficial CM 11 build for Samsung Galaxy S3 I9300 (Android 4.4 KitKat Custom ROM)

Flash Unofficial CM11 Android 4.4 Kitkat custom ROM for Samsung Galaxy S3 I9300

Samsung Galaxy S3 model number I9300 has received its own unofficial build of CyanogenMod 11. Read this entire post and you’ll manage to flash the new custom ROM without bricking the phone. However, use this post only if you wish to test Android 4.4 KitKat and CM11 builds.

The CyanogenMod team currently works on releasing the latest Nightlies based on Android 4.4. The CM 11 Nightlies should be ready for a release by the end of this month, as it has happened already will all the previous CyanogenMod official ROMs. Before starting the installation, read the preparation guide below:

  • This guide works exclusively with all the Samsung Galaxy S3 model number I9300.
    - do not attempt to flash this custom ROM with any other Galaxy S3 variant, as you will end up bricking it.
  • The Galaxy S3 has to be factory unlocked, rooted and running a custom Recovery image such as CWM or TWRP.
  • Note that you will need to run the latest versions of CWM / TWRP Recoveries.
  • The tutorial features the ‘factory reset’ step, one that will remove all data from the system partition.
    - such action removes data from system partition, which means that you will lose installed apps data, call logs info, contacts, sms text messages and all the other system data.
    - factory reset doesn’t delete data from internal storage.
  • Backup data from installed applications using the Helium app – here.
  • Backup data such as SMS text messages, call logs info or APN Internet Settings with the following Android utilities: SMS backup & restore | Call Logs backup & restore | APN Settings Backup & Restore.
    - root access might be required for some of these apps.
  • Sync all your Contacts info and People details with the default Gmail account that you’ve assigned for your Galaxy S3.
    - use the guide here if you don’t know how to it.
  • In the tutorial part of this post you’ll find be asked to create a full NANDROID Backup. This will backup all data from the ROM that is currently installed on your device.
    - make sure not to skip the backup step and create the restore point, so that in case something goes wrong with the new ROM installation, then you will be able to restore its to its previous state.
  • Go to Developer Options and enable the USB Debugging.
  • Make sure that the Galaxy S3 battery charge level is over 50%.
    - this will prevent the phone from switching off your device in the middle of the installation process.
  • Use this post only if you’re an advanced user and you know what you’re doing.
  • Don’t skip any steps listed in the tutorial and make sure to read all info.
  • If you cannot complete the guide, then you should ask for more help in comments.

How to flash Unofficial CM 11 Android 4.4 custom ROM for Galaxy S3 I9300:

  1. Download the custom ROM from here.
  2. Download the Gapps for CM 11 unofficial ROM from here.
  3. Connect your smartphone with your computer and then move both zip files to your phone’s internal storage.
    - after the files are copied, disconnect the device from PC.
  4. Power off your Galaxy S3 now.
  5. Boot the smartphone in custom Recovery Mode.
    - both CWM and TWRP are fully supported by this guide.
    - if you don’t know how to boot Recovery Mode, then follow this link.
  6. First thing that you need to do is to create a full NANDROID Backup of your current ROM:
    - CWM: select ‘backup and restore’. Save this file on your device’s internal storage.
    - TWRP: press Backup, rename the file and swipe to apply backup.
    > it is highly recommended for you to create such backup, so that in case something goes wrong during the installation, then you will be able to restore your device to a working state.
  7. Next, apply a ‘factory reset’ for your Galaxy S3:
    - CWM: select ‘wipe data/ factory reset’, then confirm this process.
    - TWRP: press Wipe, then you have to swipe the blue button to confirm Factory Reset.
    > do not skip this step, as otherwise the new Unofficial CM 11 will not boot in normal mode.
  8. Since you’ve applied all of the above, you can flash the custom ROM:
    - CWM: select ‘install zip from sdcard’, then ‘choose zip from sdcard’ option. Find the Unofficial CM 11 zip file and confirm its installation.
    - TWRP: press Install, then find the custom ROM zip. Swipe to confirm installation.
    > do not press any buttons until all files are installed successfully.
  9. When the new ROM is installed, repeat step 8 and then flash the Gapps zip.
  10. Return to the main CWM / TWRP Recovery menu when you’re done with the installations.
  11. Reboot your device now in normal mode.
    - note that the first boot process will take at least five minutes to load all the required files and you don’t have to press any buttons until the new ROM’s home screen appears.
  12. The Unofficial CM 11 Android 4.4 home screen will appear and you simply need to enter your Google Account details in order to take control over your Galaxy S3 once again.

These were all the steps that you had to take in order to complete the installation of this new custom ROM.

Note that in case the first boot process takes more than ten minutes, the devices enters into a boot loop or there are too many force closing errors appearing on your home screen, then you will need to repeat the entire tutorial once again. In case you do repeat the tutorial, then make sure that you don’t skip any steps listed above.

Ask for any extra help in comments.