Samsung Galaxy S3 I9300 Android Lollipop CM12 ROM

Samsung Galaxy S3 I9300 might not reeive the official Android 5.0 Lollipop OS update from Samsung, but its users have a good news to rejoice! Cyanogen Mod team has released an unofficial custom ROM CyanogenMod 12 ROM based on Android 5.0 Lollipop for Samsung Galaxy S3 – I9300 smartphone.

It might be better if it comes to your knowledge that this CyanogenMod12 ROM is still in its alpha stage which means it can bring in a few unresponsive features. However, as of now, there is no major issue that came up by installing this, says Team Android. So, you may proceed without having the fear of any new bugs that it may bring.

You can install the CM12 ROM by downloading it through the link given below and also by following the step-by-step procedure given here in the post. Note that we at Celtec at not responsible if your device gets bricked during any stage of the installation. We advise you to proceed at your own risk.

Before you start installing, check…

– that the Galaxy S3 device you have bears the model number I9300. This is because the CM12 ROM is designed only for the I9300 devices. Go to Settings -> About Phone to verify the model number.

– if your phone’s battery has at least 80% charge. It is always advisable to start installation with a 100% charge in the phone.

– Take backup of all the data and settings in your phone. How to take backup of Android phone.

– You should have all correct USB drivers of your Galaxy S3 I9300 smartphone installed properly in your computer that you are going to use for the installation.

Download Samsung Galaxy S3 USB drivers from here

– Enable USB debugging mode on your phone by going to Settings ->Developer Options (for Android 4.0 or higher) or by going to Settings -> Applications -> Developments (for Android 2.3 or earlier).

– Ensure that the device is rooted with CWM Recovery installed and its bootloader is unlocked

Download the following files on your computer:

CyanogenMod 12 Android 5.0 Lollipop ROM

Google Apps

Steps to install CM12 ANdroid 5.0 Lollipop ROM on Galaxy S3 I9300:

1. Connect your phone via a USB cable to your computer and mount the phone’s USB mass storage

2. Copy the downloaded CM12 ROM zip file from your computer to the root folder on the phone’s SD card.

3. Switch off the phone and disconnect it from the computer and the USB cable.

4. Press the Volume Up+ Home + Power buttons together at a time and boot the device into Recovery Mode.

5. Now, the phone enters into CWM Recovery and once this is done, perform a full data wipe by selecting Wipe Data/Factory Reset.

Use the volume up/down button to navigate and the power button to confirm.

6. Then select Wipe Cache Partition.

cm12 rom on galaxy s3 i9300


Image Source: Android Team

7. After that, go to advanced and select Wipe Dalvik Cache.

8. Return to the main recovery Mode and select Install Zip from SD card.

9. Select Choose Zip from SD card. Select the CM12 ROM zip file by navigation with the volume buttons and press power button to confirm selection.

10. Once the CM12 ROM installation begins, repeat steps 8,9 to install the Google apps as well.

12. When the CM12 ROM and Google apps installation is successfully completed,  go to +++++Go Back+++++ and select Reboot System Now option from the Recovery Menu.

The phone will attempt to reboot then and the first boot will take about five minutes to complete. So have patience and wait till you see the home screen after the reboot is done.

After the reboot is done, go to Settings -> About phone and verify the latest firmware on your phone.


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Read more of: Android 5.0 Lollipop