Install Official CM 10.2 Nightly ROM for Samsung Galaxy S3 I9300 (Android 4.3 Jelly Bean Custom ROM)

Install CM 10.2 Nightly ROM for the Samsung Galaxy

The official build of CM 10.2 Nightly ROM has been released for the Samsung Galaxy S3 I9300. Now you can use this tutorial in order to learn how to successfully update the device. Read this entire post and make sure that you don’t skip any steps listed here.

In order to successfully update your device at your first attempt, you need to take a look at the preparation info below:

  • Use this guide only with the Samsung Galaxy S3 model number I9300. This is the International model of the SGS3.
  • Do not try to flash the files that you find here on any other smartphone.
  • Your phone has to be rooted, unlocked bootloader and one of the CWM or TWRP Recoveries are supported.
  • The tutorial will factory reset your device and this means that all contents from the system partition. The installed apps data, SMS and other similar files will be removed in the process.
  • If you’re planning on saving installed apps data, then you should use the Helium app from Google Play Store (here) or the Titanium Backup (here).
  • To backup SMS, Call Logs and APN Internet Settings use the following tools for Android: SMS backup & restore | Call Logs backup & restore | APN Settings Backup & Restore. Root access is required for some of these tools.
  • Sync your Contacts info with the Gmail account that you’ve assigned as default for your SGS3.
  • Enable USB Debugging from the Developer Options menu.
  • Make sure that you know what you’re doing before starting the update as we cannot be blamed in case something goes wrong. We can’t be held responsible in case you brick the phone or your lose any data files.
  • Read the entire post, make sure not to skip any steps and that you ask for more help in comments in order to make sure that you complete the installation at your first attempt.
  • The phone’s battery should have at least 50% power left in it before switching off. In case the device powers off in the middle of the updating process, then you will be forced to repeat the entire tutorial once again.

Now that you know all that, you can continue to the next part of this article and learn how to successfully update your SGS3 to Android 4.3 via CyanogenMod 10.2 Nightlies ROM. Remember that this is not a final build and you will find bugs and errors while using it.

How to update Samsung Galaxy S3 I9300 with Official CM 10.2 Nightly ROM build:

  1.  Download CM 10.2 Nightly ROM file from here.
    - get the latest build and don’t extract its contents.
  2. Download Gapps for Android 4.3 custom ROMs from here.
    - do not unzip the archive.
  3. Now you need to connect the phone with your computer. Copy both zip files to your SGS3 internal storage.
  4. After you’ve moved the files, disconnect the device from PC. Power off the phone completely.
  5. Boot the device into CWM or TWRP Recovery Mode. Both recovery modes will work with this tutorial.
  6. First you need to create a NANDROID backup of your current ROM.
    - TWRP Recovery: press Backup, then select the system parts that you want to save. Confirm the process.
    - CWM Recovery: select ‘backup and restore’, use the backup option and save the files on your device. Confirm.
  7. Now you need to ‘factory reset’ your phone:
    - TWRP Recovery: press ‘wipe’, then ‘factory reset’ button. Confirm.
    - CWM Recovery: select ‘wipe data/ factory reset’ option. Confirm the process and then continue to the next step.
    > in case your device is already sporting a previous build of CM 10.2, then you can skip this step 7 and flash the new ROM version over it.
    > however, in case your phone doesn’t boot with the new OS, then you will be forced to return to this step and apply factory reset.
  8. Next, install the CyanogenMod 10.2 Nightly ROM:
    - TWRP Recovery: press the ‘Install’ button. Then browse your device’s internal storage for the CM 10.2 Nightly zip. Load it into TWRP and confirm the installation.
    - CWM Recovery: select ‘install zip from sdcard’, then ‘choose zip from sdcard’. Find the CM 10.2 Nightly zip. Confirm that you want to install it.
    - the installation shouldn’t take more than a couple of minutes. Continue to the next step when done.
  9. Now you have to flash the Gapps file. Repeat step 8 and find the Gapps zip, then confirm the installation.
  10. When both files were installed with success, return to the main CWM / TWRP Recovery screen. Reboot your smartphone.
  11. The home screen of CM 10.2 Nightly / Android 4.3 custom ROM will appear after a couple of minutes. Enter your Google Account details and take control over your device once again.
  12. Test all of its new features, then tell us in comments if you’re satisfied with it.

These were the steps that you needed to follow in order to update your device with a brand new CM 10.2 Nightly ROM. In case you cannot complete the update or you get stuck at some step listed above, then you should ask for more help. Also, if you’ve applied all steps but the device doesn’t boot into normal mode, then you should repeat the entire tutorial without skipping any steps, make sure to apply ‘factory reset’.

I hope that you did manage to update your Samsung Galaxy S3 I9300 and that now you’re testing one of the most popular Android 4.3 AOSP custom ROMs.

If you don’t like how your device is working with this new ROM, then you can easily restore your phone to its previous ROM using the NANDROID Backup file created in step 6. If you do like this new ROM, then you should know that you can continue to update it with the latest Nightly builds using the CM Updater, a tool that can be found under Settings menu.

Remember to create NANDROID Backups of installed ROMs every time you’re about to flash any new ROMs.