Galaxy S3 users can install Android 4.1.2 Jelly Bean by using a new update of RootBox custom ROM. This is not official Android 4.1.2 update but a Custom ROM, there is no any update regarding OTA yet.
You need a rooted device to use the Custom ROM. Install “Root Checker” from Google Play to find if your device is rooted.
The guide mentioned below is only for Samsung Galaxy S3 I9300 and not for any other device. You can check your device model number by going to Settings >> About Phone.
We cannot be held liable of any damage done to your device while following the below mentioned procedure.
Install Android 4.1.2 Jelly Bean on Galaxy S3 using RootBox Custom ROM
Take a complete backup of data,apps and settings as the procedure may wipe your data.
Make sure that the battery of device has a minimum charge of 60%.
Enable “USB debugging” on your device by going to Settings >> Developer options >> Enable USB debugging.
Install ClockworkMod Recovery on Galaxy S3.
Download RootBox ROM from here and Google Apps Package from here.
Without extracting the zip files copy both the files to your device SD-Card.
Switch off device and enter into recovery mode. To enter recovery press and hold the Volume Up and Volume Down and Power buttons.
Take a Nandrop back up of your existing ROM. Select Backup and Restore option from the recovery mode and then select backup again.
Select “wipe data/factory reset” and confirm to wipe all data. Wipe “Dalvik Cache”.
Select “install zip from sdcard” and then select “choose zip from sdcard”. Navigate to RootBox ROM file and select to install. Wait for few minutes till the installation gets complete.
Repeat the procedure to install Google Apps Package.
Select “go back” and then select “reboot system now”.
Android 4.1.2 Jelly Bean on Galaxy S3 is installed using RootBox Custom ROM