You are going to learn how to update your Samsung Galaxy S3 to JellyBean 4.1.2 by flashing ROOTBOX firmware.
The rooting operation is a complex process and you should know that backup must be performed.
Below, we are sharing a different methods to save your data. First you need to save the existing ROM with the help of CWM recovery tool. After that, you can download the call log backup and restore software. For the SMS text messages, you can download SMS backup and restore apps. For Contacts, we recommend using synchronization for contacts with the Google account
Backup the EFS folder and copy it on an external PC or use the SD card for saving other files
You should be aware that when you root your phone warranty will be lost and in order to restore it you must make a downgrade or you have to wait for an OTA update available released by Samsung. Other significant step is to download and install a Custom Recovery Image on your Samsung Galaxy S3.
- You will need a Windows PC, and an available USB port, also you will need the original device USB cable.
- Deactivate/disable the security level of protection on both, PC and SG3 (antivirus, firewalls) because these can interact with the rooting process.
- Verify the level of charge battery for your device and make sure it is now below 50 %.
- On your SG3, go to “Settings -> Applications -> Development -> USB debugging” and enable the latter option USB debugging.
Verify to have at least 1GB free memory on the SD card.
Update Galaxy S3 to Jelly Bean 4.1.2 with RootBox Custom ROM Firmware
- Download the Root Box Jellybean 4.1.2 Custom ROM Firmware on your computer.
- Download the Google Apps package on your computer
- Connect your device to the PC via its USB cable.
- Copy the downloaded files on your phone.
- Disconnect the smartphone from the computer and reboot it in the Recovery Mode.
- Now, from Recovery Mode, Select “wipe data factory reset” and then “wipe cache partition”.
- Go to the main menu from recovery by pressing on “+++go back+++”.
- Select “install zip from SD card” and then “choose zip from SD card”.
- Select the update file and then flash it.
- Repeat the same procedure for flashing the Google Apps package.
- Now you must wait until the end of the rooting process.
- When the flashing job is done you need to take “+++go back+++” and after that “reboot system now”.
That it’s all, you have now learnt how to install the Android Jelly Bean 4.1.2 based RootBox custom ROM firmware on your Samsung Galaxy S3 smartphone.