How to Update Samsung Galaxy S3 I9300 with Phenom Android 4.1.2 Jelly Bean Custom Firmware

Samsung Galaxy S3 is the popular device and pick of many Android developers. Phenom ROM is one such custom firmware of Galaxy S3 GT-I9300. It’s based on the official Android 4.1.2 Jelly Bean release, although it has been customized to add in more add-ons to provide enhanced looks and feels for your Galaxy S3. One of the biggest additions is the integration of HTC Smartphones famous Beats Audio software which comes when you install this firmware on your device.Galaxy S3


As you read this article further-on, we will guide you on how you can update your Galaxy S4 GT-I9300 with the Phenom Android 4.1.2 firmware release. But before updating you should ensure the following precautionary measures have been followed.Galaxy S4 Phenom ROM

  • You should have enabled the USB debugging on your phone. To enabled it go through Menu > Settings > Developer Options and ensure that USB debugging is ticked.
  • You should also check that battery life on your device should be atleast 50%.
  • You should take backup of apps, SMS, Contacts, Call logs on your Device by any usual methods that you usual follow.
  • You should have Galaxy S3 install with ClockWorkMod Recovery.
  • Your phone should be rooted as well.

Note: This custom firmware belongs to the respective developer/owner. We at have just provided the tutorial for updating your device. So we held no responsibility if you damage or brick your phone. Although if you follow the procedure mentioned here correctly things will go smoothly without any trouble to your device.

Galaxy S3 Updating Procedure

Here is the complete step by step procedure to update your Galaxy S3 with Phenom ROM –

  • Download the Phenom Android 4.1.2 Jelly Bean ROM for Galaxy SII on to your PC.
  • Connect your Galaxy S3 using the USB cable and mount the SD Card.
  • Now Copy/Move the Android 4.1.2 ROM zip file to the root of your SD card.
  • Then turn OFF your phone and disconnect it from USB Cable.
  • You need to enter your Galaxy S3 in recovery mode. This can be done by going holding the Volume UP + Home + Power button altogether at once. The recovery mode here is ClockWorkMod Recovery.
  • Once you are in the CWM Recovery, from Menu first take backup of your device by going through Backup and Restore and then select backup current ROM. For your information in recovery mode, Volume UP/Down Keys are used as navigation keys among the options and Power button is used to select the highlighted option.
  • Now perform full date wipe by selecting “Wipe Data/Factory Reset”.CWM Recovery
  • Then select “Wipe Cache Partition”. Also Wipe the Dalvik Cache by going through Advanced > Wipe Dalvik Cache.
  • Then go back to the main recovery screen and then select “Install Zip from SD card”.
  • Now select “Choose Zip from SD card” using the Volume keys and browse through the Android 4.1.2 ROM zip as saved to SD card.
  • Once the installation is done, hit “+++++Go Back+++++” and to reboot hit “reboot system now” from the recovery menu.

Your Samsung Galaxy S3 GT-I9300 is now installed with the Phenom ROM and it will take up to 5 minutes to boot your device for the first time with the latest firmware.

Note: If your phone doesn’t boot, remove and re-insert battery once. It will solve the issue of booting.

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