Official CM 10.2 ROM for Galaxy S3 I9300 (Android 4.3 Jelly Bean)

Install  CM 10.2 Stable Android 4.3 Jelly Bean ROM for Galaxy S3 I9300

The Samsung Galaxy S3 I9300 device has received the official CyanogenMod 10.2 Stable build which is based on Android 4.3 Jelly Bean platform.

This step by step guide is provided for all Galaxy S3 owners who want manually install the Android 4.3 stable build from CyanogenMod platform.

The last CM 10.2 is a stable custom ROM and brings with all Android 4.3 Jelly Bean features and in additional with other proprietary features and applications.

The next part of our guide will show you how successfully install the new CM 10.2 stable custom ROM for Samsung Galaxy S3 model number I9300:

• This step by step guide is provided only for Samsung Galaxy S3 model number I9300, do not use this guide for any other incorrect device.
• The Samsung Galaxy S3 needs to be rooted and additionally it needs to run the latest CWM or TWRP Recovery image. Without the root access and a custom recovery image (such as CWM or TWRP recovery) you cannot complete the guide.
• Before flashing the new custom ROM a ‘factory reset’ action is required. The wipe action will delete all data from the system partition, but the data stored into internal/external storage won’t be affected.
• Do not skip the ‘factory reset’ action, as the Samsung Galaxy S3 device will not boot in normal mode.
• Create a backup for all your important data is required, and also create a full NANDROID backup for the actual running ROM.  The NANDROID backup will represent a restore point for your S3 device, and in case you want to restore it you can do this if the new custom ROM doesn’t work very well.
• You can use the Helium application for get the backup for your data; the Helium application is available on Google Play Store via this link.
• Backup your SMS text messages and the device’s APN Internet Settings by using suitable tools, also you can use the SMS backup and restore application, and APN Settings Backup and Restore from here. (For these applications,  the root access is required).
• Save your stored contacts using a sync method with your Gmail account,
• Enable the USB Debugging mode from Developer Options.
• Ensure that the device’s battery has more than 65 % power left. This charge level is required to prevent a forced power off in the middle of the installation process.
• Remember that, this is a step by step guide for advanced Android users, so knowing this do not skip any steps from below.
• All instructions and files listed here are provided only for educational and instructional purpose, so we cannot be held liable or responsible for any data lost or damage of the device during or after the installation process. Users are adviced to use this guide on their own risk only.

How to install the CyanogenMod 10.2 Stable ROM based on Android 4.3 for Galaxy S3 I9300

1. Firstly, download the CM 10.2 file from here.
2. Secondly, download the Gapps for Android 4.3 ROMs from here.
3. Now, connect the device to computer using the USB cable.
4. Copy both downloaded zip files to Galaxy S3 internal storage.
5. Do not unzip the copied files.
6. After the transfer file operation is done, you can disconnect the smartphone from Computer.
7. Turn off the phone now
8. Boot the smartphone into CWM or TWRP Recovery mode now. 
9. Now, create a full Nandroid backup for the installed ROM, to do this from CWM you need to select “backup and restore” and then save the backup file. For the TWRP Recovery tool,  you need press Backup and after that rename the file and save it on the S3 device.
10. Apply the “Factory Reset” operation. To do this from CWM select the ‘wipe data/ factory reset’ and then confirm and from TWRP Recovery press Wipe option then swipe to confirm the Factory Reset process.  Important: Don’t skip this step as the new custom ROM won’t boot successfully.
11. Now, you can move to the installation of the new CM 10.2 custom ROM based on Android 4.3 Jelly Bean firmware for Samsung Galaxy S3 device.
12. For the S3 device with the CWM recovery tool select: ‘install zip from sdcard’ and then ‘choose zip from sdcard’ find and load the new ROM zip file and confirm to install the same.
13. For the S3 device with the TWRP recovery tool press Install and then find the internal storage for the copied CM 10.2 stable ROM zip file and confirm the installation.
14. Now, don’t press any buttons until the installation process isn’t complete.
15. After the new CM 10.2 is flashed repeat the steps 12 and 13 and install the Gapps zip file too.
16. After the both files are successfully flashed, return to the main custom Recovery Menu.
17. From the main menu of Recovery menu select reboot system now.
18. Note: the first reboot take longer time to be completed, so you shouldn’t press any buttons until to see the home screen of the Cyanogen Mode 10.2 ROM firmware.

Congratulation, you’ve successfully learned how to install the new stable custom ROM CM 10.2 build on Android 4.3 Jelly Bean OS on Samsung Galaxy S3 device.

If you don’t like the new CM 10.2 stable ROM you can also restore the smartphone to its previous rom by using the Nandroid ROM backup file that you’ve created above.

source: android.sc