T-Mobile users who own the Samsung Galaxy S3 can update their smartphones to Android 4.1.2 Jelly Bean via the SynergyROM, which brings several improvements and new features.The users look very happy with the performance of the new firmware, however when they can get something more in any other firmware they would be happier.
– Before you go ahead with the installation process, keep one thing in mind: there are always chances of the device experiencing bricking issues. That only happens if the rooting is not done properly and the instructions are not followed step-by-step.
– Remember to read through the instructions before beginning.
– Remember to back up important data.
– Ensure your phone’s battery power is at least 85 percent, if not fully charged, to avoid disruption due to power loss.
1: The process is meant only for AT&T Samsung Galaxy S3 SGH-T999. Therefore, users are advised to check their devices’ model number in: Settings > About phone.
2: Make sure the device has at least 80 percent of battery backup.
4: Back-up all your important data.
5: Download and install ClockworkMod recovery.
6: Download SynergyROM Android 4.1.2 ROM.
7: Download Google Apps
8: All the custom ROMs, firmware, official firmware updates, tools and anything mentioned in this tutorial belong to their respective developers. Mobile&Apps will not be held responsible for anything that goes wrong.
Now you are all set to start the smooth task; just follow the instructions given below step-by-step:
1: Connect your Galaxy S3 to your computer via micro USB cable.
2: Copy and paste the downloaded SynergyROM Android 4.1.2 ROM to your phone.
3: Switch the device off and detach the USB cable.
4: Press and hold the Power + Volume Up + Home Button to enter ClockWorkMode Recovery.
5: In Recovery menu, you are always recommended to perform a full Wipe Data/Factory Reset to avoid crashing and ROM compatibility issues. It is an optional step if you upgrade from your previous ROM version. For CWM recovery, use Volume key to navigate in Recovery Mode. For TWRP, use touchscreen to navigate in Recovery Mode.
6: Do Wipe Cache Partition – Select from the menu and select Yes to confirm.
7: Go to advanced and do Wipe Dalvik Cache – Select from the menu and select Yes to confirm.
8: From the main menu in Recovery, select the install zip from SDcard, then select choose zip from internal SDcard, browse to folder location and select the SynergyROM Android 4.1.2 ROM and click Yes to install.
9: Back to main menu in Recovery, select the install zip from SDcard, then select choose zip from internal SDcard, browse to folder location and select the Google Apps file and click Yes to install.
10: After the installation completes, go back to recovery’s main menu.
1. Select reboot system now to reboot the phone.
2. For first boot up, it normally takes a longer time. Please wait patiently.
Source : mobilenapps