How To Update Samsung Galaxy S3 GT-i9300 to Android 4.2 Jelly Bean...

How To Update Samsung Galaxy S3 GT-i9300 to Android 4.2 Jelly Bean [Ultimate Guide]


The latest Android 4.2.1 Jelly Bean update is now possible for Samsung Galaxy S3 GT-i9300 although not officially. Samsung used the new Exynos 4412 quad-core processor for the Galaxy S3, it is clocked at a frequency of 1.4 GHz which is high alright. The Exynos 4412 quad-core processor comprises of Cortex-A9 CPU cores with Mali GPU co processors and is offered with 1GB RAM and 16GB of internal storage, this can be further expanded to another 64GB via a microSD card.


The Galaxy S3 sports a rear-facing 8 megapixel flash camera with 1080p video playback and a secondary front-facing camera. OS wise the latest Android Ice Cream Sandwich (4.0) is used.

Read the following instructions carefully while updating your Samsung Galaxy S3 GT-i9300 to Android 4.2.1 Jelly Bean. Please note that each and every step mentioned in this article is important.

Disclaimer: The procedure given in this tutorial is considered as risky and may cause damage to your phone. It is recommended that you should not follow it unless you are familiar with these things. Follow this guide completely at your own risk.

To update Samsung Galaxy S3 GT-i9300 to Android 4.2.1 Jelly Bean, follow our guide below.

I. Before You Begin:

1. The following procedure works for Samsung Galaxy S3 GT-i9300 Smartphone.

2. Make sure your device have at least 80% battery power.

3. You must have ClockworkMod Recovery installed on your device.

4. Make sure USB Debugging is enabled

II. Downloading Required Files:

1. Jellybean 4.2 Package for Samsung Galaxy S3 GT-i9300. [Filename:]

2. Google Apps [Filename:]

III. Install Android 4.2.1 Jelly Bean ROM on Samsung Galaxy S3 GT-i9300:

1. Connect your Samsung Galaxy S3 GT-i9300 to PC using USB cable.

2. Copy downloaded files to the SD card of your Phone.

3. Disconnect USB

4. Turn off your Phone.

5. Boot into recovery by pressing and holding Volume Down, Home and Power buttons

6. Wipe the Data and Dalvic Cache or you might brick your device afterwards

7. Select install zip from sdcard, then select choose zip from sdcard. (locate the Jelly Bean 4.2 Rom .zip file) and select it by pressing Power button.

8. Once the ROM installation process end, repeat the step 7 but choose Google apps instead of ROM zip to install the Google apps package.

9. When installation is completed, go back to the main recovery menu and select reboot system now to reboot the phone and boot up into customized Android 4.2.1 ROM

Congrats! Android 4.2.1 Jelly Bean firmware based custom ROM is now installed and running on your Samsung Galaxy S3 GT-i9300 smartphone

If you have any questions about your mobile phone, you can drop us a message. We will try to answer it with any available solutions.

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