Galaxy S3 I9300 is among the lucky few Android devices to enjoy a spate of custom Android 4.3 updates lately, such as ParanoidAndroid v3.97, Nexus-styled SuperNexus 3.0 ROM, CyanogenMod 10.2 ROM and SlimBean Build 8.0 ROM. Now, the Carbon AOSP ROM brings the latest custom Jelly Bean upgrade for the Galaxy smartphone with its features borrowed from popular custom ROMs such as CyanogenMod, AOKP, ParanoidAndroid and AOSP.

NOTE: Instructions provided in this guide are meant for reference purpose only. IBTimes UK will not be held liable for any device damage during or after firmware installation. Users are advised to proceed at their own risk.


Galaxy S3 I9300

    • Carbon AOSP ROM and the instructions provided in this guide are applicable to the international variant - Galaxy S3 GT-I9300 model only. Do not attempt these instructions on any other device, as it may inadvertently brick or damage the device. Verify the device's model number by navigating to Settings > About Phone.
    • Back up important data and settings on the phone by using one of the recommended custom recovery tools such as ClockworkMod (CWM) or TWRP, as it creates a complete image of the existing phone setup.
    • Ensure the device has at least 80% battery charge to prevent unexpected device shutdown (due to battery drain) during firmware installation.
    • Make sure that your phone is factory unlocked and rooted with CWM recovery installed on it.
    • Enable USB Debugging mode by navigating to Settings > Developer Options (if phone is running Android 4.0 or later) or go to Settings > Applications > Development (if running Android 2.3 or earlier). If the device is running Android 4.2, then perform the following steps:
        • Go to Settings > About Phone
        • Scroll down to the bottom of the screen and select Build Number
        • Tap Build number seven times to unlock or reveal hidden Developer Options. Now, select the checkbox to enable USB Debugging mode under Settings > Developer Options.

How to Install Android 4.3 Jelly Bean on Galaxy S3 GT-I9300 via Carbon AOSP ROM

Galaxy S3 I9300
Galaxy S3 I9300 gets Android 4.3 Jelly Bean via Carbon AOSP ROM .
    • Connect the phone to computer with original USB cable and copy the downloaded Carbon AOSP ROM and Google Apps zip files to the root folder on the phone's SD card.
    • Power off the phone and boot it into Recovery mode. To do so, press and hold Volume Up and Home buttons together and then simultaneously tap the Power button until the green robot icon with a triangle appears on the screen. This confirms entry into Recovery mode.
    • Before flashing the new ROM do the following steps in CWM recovery:
      > wipe data/factory reset
      > wipe cache
      > go to "advanced" and perform wipe dalvik cache
      > go to "mounts and storage" and format system
    • In CWM recovery, click Install Zip from SD card and select the ROM zip file copied earlier to the phone's SD card (repeat this step for installing Google Apps as well). After selecting the ROM file, allow the ROM to be installed on the device. This process may take about five minutes to complete.
    • After the device is updated, hit Reboot System Now to reboot the phone into the newly installed ROM.
    • Carbon AOSP ROM is now successfully installed on your Galaxy S3 GT-I9300. Go to Settings > About Phone to check the firmware version installed.

[Source: XDA Developers]