A new Custom ROM named as BlackJelly is available for Sprint Galaxy S3 users by XDA Senior Member DroidModder. The ROM is based on Android 4.1 Jelly Bean ROM along with some new features. It is not an official ROM by Samsung or Sprint.
The guide mentioned below is only for Sprint Galaxy S3 model number SPH-L710 and will not work with any other variant.You can check your device model by going to Settings >> About Phone.
We cannot be held liable for any loss or damage done to your device while following the guide.
Install BlackJelly ROM on Sprint Galaxy S3 SPH-L710
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 Sprint Galaxy S3 .
Download BlackJelly ROM from here and copy the file to the SD-Card of your device without extracting.
Switch off device and enter into ClockworkMod recovery. Hold power button and volume down button and enter recovery.
Take a Nandrop backup of your existing ROM so that you can revert if required. Select “Backup and Restore” and then select “Backup” again.
Select the option of “wipe data/factory reset” to wipe all the data. Select “Advanced” then select “Wipe Dalvik cache” to clear Dalvik cache aslo.
Select “install zip from sdcard” and then select “choose zip from sdcard”. Navigate to the “ROM” file which you have downloaded and confirm to “install”. Wait till for few minutes.
Select “go back” and then select “reboot system now”.
BlackJelly ROM Based On Android 4.1 Jelly Bean is installed on Sprint Galaxy S3.