How to install any official firmware on Samsung Galaxy S3

The best things about official firmware are that you can easily install or update them on your phone, battery life is greater, are much more stable than Custom Roms, you don’t need to root the phone in order to install them, and therefore you won’t lose your warranty and no backup is needed because you won’t lose your data after flashing a new official firmware. Of course, that advice is available for all smartphones running on Android OS, but this post shows you how to install any official firmware for Samsung Galaxy S3. If your phone is rooted, there is no problem because after installing the official firmware, the rooted Kernel is automatically replaced by a new fresh unrooted one.

Warning!

• This guide applies just for Samsung Galaxy S3 GT-I9300
• Use these guidelines at your own risk, we are not responsible for any damage you could do to your phone.
• This tutorial worked for us and it should work for you too, therefore this guide was tested first
• Read all the instructions carefully before attempting to install the firmware
• If you encounter any problems don’t hesitate to write a comment

Requirements

• Make sure you have installed the latest Samsung drivers or have installed the latest version of Samsung Kies on your computer
• Make sure you have downloaded the latest version of ODIN, the official Samsung tool
• Disable any antivirus software that could interfere with ODIN
• Make sure you first close Samsung Kies
• Charge up your phone for at least 50%

Guide:
Step 1. Download any official firmware.zip and extract any official firmware.tar to your desktop
Step 2. Download Odin 1.85.zip and extract it on your computer
Step 3. Power off your device
Step 4. Start your device in Download Mode by pressing and holding simultaneously Volume Down, Home and Power buttons until the screen lights up and then press Volume Up to continue
Step 5. Open Odin and then connect your Samsung Galaxy S3 to your computer using the USB cable
Step 6. Hit the PDA button and select any official firmware.tar
Step 7. Make sure you haven’t checked the Re-partition and Flash Lock options and then hit the Start button
Step 8. When the process is finished ODIN should say PASS and your Samsung Galaxy S3 will reboot, now you can unplug your phone from the computer
Now your device should reboot the new official firmware with all your old settings.