Update Samsung Galaxy S3 LTE I9305 to Android 4.3 JB using Official CM 10.2 Nightly ROM

Install CM 10.2 Nightly ROM for the Samsung Galaxy

The official build of CM 10.2 Nightly ROM is here and you can install it on the LTE variant of the Samsung Galaxy S3 using the info listed in this article. Read all instructions, don’t skip any steps and you should be able to flash the most popular Android 4.3 Custom ROM currently available.

In order to flash this update from the first try, you need to take a look at the preparation guide below. These guidelines will teach you how to successfully install the new files without repeating the tutorial. If you don’t understand some of these instructions, then you can ask for more help in our comments field. Here’s what you have to know:

  • This build of CM 10.2 Nightly that you will find several lines below will work exclusively with the Samsung Galaxy S3 LTE with the model number I9305.
  • Don’t use this tutorial with any other device as you will brick it.
  • The Galaxy S3 LTE that you’re about to update with CM 10.2 Nightly should be rooted and running a custom Recovery image.
  • Both CWM and TWRP Recovery are supported by this guide and you will manage to complete the update without problems.
  • In the ‘how-to- part of this guide you will find a step that tells you to wipe data and factory reset the phone. This is destined to be used on devices that are currently running different ROMs. Users with older builds of CM 10.2 Nightly can skip the ‘factory reset’ and overwrite the current one.
  • If you apply ‘factory reset’ the contents stored on your phone’s system partition will be deleted. So, files such as installed apps data, SMS and other similar ones will be completely removed.
  • To backup installed apps data you should use Helium (here) from Play store, or the Titanium Backup app (here).
  • If you want to save data like SMS, Call Logs info and APN Internet Settings use these utilities: SMS backup & restore | Call Logs backup & restore | APN Settings Backup & Restore. Root access is needed for some of these small tools.
  • Also, sync Contacts with your Gmail account.
  • Read the entire tutorial, don’t skip any steps and make sure to use the comments field in case you cannot complete the update.
  • Enable USB Debugging from the Android Developer Options menu.
    - if the Developer Options doesn’t show up in Settings, then you need to open About Phone and tap seven times on the ‘build number’ section to unlock Android development.
  • This is a guide for more advanced users, do not try to update your device in case you don’t know what you’re doing.
  • Make sure that the Galaxy S3 I9305 battery has enough power left in it before starting the installation. If the device powers off during the install process you will need to repeat the entire tutorial..

Now that you’ve taken a look at all the extra info listed above, continue to the tutorial guide and learn how to update your smartphone.

How to flash CM 10.2 Nightly ROM for the Samsung Galaxy S3 LTE I9305:

  1. Download the CM 10.2 Nightly build ROM from this link here.
    - get the latest build of this ROM.
    - do not unzip the archive.
  2. Download the Gapps for Android 4.3 custom ROMs from here.
  3. Next, connect the Galaxy S3 I9305 with the computer using the USB data cable.
  4. Move both files to your device’s internal SDcard. When the files are copied, disconnect the phone from computer.
  5. Power off the Galaxy S3 now.
  6. Boot it into CWM or TWRP Recovery Mode. It depends on which custom recovery image you’ve installed on your device.
  7. Before starting the installation of the ROM, you will need to create a NANDROID Backup of your current ROM:
    - CWM Recovery: select the ‘backup and restore’ option first. Next, use the ‘backup’ option and save the NANDROID ROM Backup file to your phone’s internal SD.
    - TWRP Recovery: press Backup button, then select the files you wish to save. Confirm.
    - the backup should take a while, so you need to wait until is complete without pressing any buttons.
  8. Next, apply the factory reset:
    - CWM Recovery: select ‘wipe data/ factory reset’ step. Confirm this action.
    - TWRP Recovery: press Wipe, then Factory Reset. Confirm the process.
    - NOTE: if your phone already runs on a previous CM 10.2 Nightly build, then you can skip this step.
    - if the phone doesn’t boot after you install the new ROM and you didn’t apply ‘factory reset’, then you will have to return to Custom Recovery Mode and apply ‘factory reset’, as it will force it to boot into normal mode.
  9. Now install the CM 10.2 Nightly ROM:
    - CWM Recovery: select ‘install zip from sdcard’, then ‘choose zip from sdcard’. Find the CM 10.2 Nightly ROM and confirm the installation.
    - TWRP Recovery: press Install, browse your internal storage and load the CM 10.2 Nightly zip. Confirm that you want to install it.
    - the installation process should take several minutes to flash all files. Don’t press any buttons.
    - when the installation is complete, move to the next step.
  10. Flash the Gapps for Android 4.3 custom ROMs using the same actions as in step 9. After you manage to complete the installation of both CM 10.2 and Gapps files, return to the main custom Recovery screen.
  11. Now you can reboot your Galaxy S3 I9305 into normal mode.
    - note that the first boot process of this new ROM will take a while before loading all the required files.
  12. Enter the Google Account details when the home screen of CM 10.2 Nightly appears.
  13. Start testing the ROM and see which are its best new features.

I hope that you’ve managed to update your Samsung Galaxy S3 LTE I9305 phone using this tutorial. If you get stuck or you cannot complete the installation, use the comments field to ask for extra help. Make sure to leave a detailed comment so that we will be able to come up with a viable solution for any problems that you might have encountered in the process.

In case the Official CM 10.2 Nightly ROM zip doesn’t install correctly at your first attempt and the phone doesn’t seem to boot into normal mode, then you should boot again into CWM / TWRP Recovery and repeat the entire tutorial once again. Make sure not to skip any steps that I have listed above and that you apply the ‘factory reset’ one in case you’ve skipped it the first time.

In case you find major bugs or you don’t like this new ROM, then you can always restore your device to its previous ROM using the backup file created in step 7. Use the same Custom Recovery mode. If you have any other questions, use the comments section below.