Samsung Galaxy S3
Samsung Galaxy S3 (Credit: Vinith Devdas via Wikimedia Commons under Creative Commons Attribution-Share Alike 3.0 Unported license).Vinith Devdas via Wikimedia C

A new CyanogenMod Android 5.0 Lollipop CM12 series custom ROM has been made available to the Samsung's 2012 flagship smartphone Galaxy S3 LTE model.

This new custom firmware is CyanogenMod CM12 series  version and is developed by a recognized XDA Developer forum member going by the moniker, DerTeufel1980. Other contributor includes - sbrissen.

It is 225.1MB in size and this custom ROM is based on the AOSP (Android Open Source Project) 5.0.2 Lollipop.

This is an experimental CM12 Alpha build (unstable), so some issues are yet to be fixed. We advise our readers to go through the whole tutorial article first before going ahead with the custom ROM installation.

Prerequisites (things to remember before installing Custom ROM):

  • This new CM12 custom ROM series Android 5.0.2 Lollipop firmware has to be installed on the Samsung Galaxy S3 GT-I9305 LTE model only; if tried on other devices, it might get bricked [To check your device model: Go to Settings >> About phone >> model number]
  • Make sure the device is rooted before going forward for custom ROM installation
  • Installation of custom ROM requires clearing of memory in the smartphone, so make sure to back all the data by installing TWRP in the smartphone.
  • Users make sure you have installed USB drivers on the PC, or else your smartphone (Samsung Galaxy S3 I9305) will not be recognised by the computer.
  • Make sure your device has more than 80% battery, or else there is chance of smartphone getting temporarily bricked if the installation process is interrupted midway.
  • Though installing custom ROM improve the device's performance and UI experiences, it makes the company warranty void and they will no longer be liable to provide updates in future [users can restore warranty by flashing the device with stock-ROM].

[Disclaimer: This procedure is very technical and should be performed by a person with sound knowledge of rooting (or manual software installation) Android devices. If the step-by-step installation process is not followed properly, there are chances of the smartphone getting bricked or being permanently irreparable. International Business Times, India Edition cannot be held responsible for any damage or claims from readers if the procedure does not yield the required results or if the smartphone is bricked. Hence, users are advised to proceed with caution.]

Tutorial: Step-by-step installation guide of CyanogenMod [Unofficial] Android 5.0.2 Lollipop CM12 Alpha custom ROM on Samsung Galaxy S3 GT-I9305-

Step 1: Download CyanogenMod [Unofficial] Android 5.0.2 Lollipop CM12 Alpha custom firmware (build date: 2014-12-21) - (HERE) and Google Apps (HERE/ HERE) in to your PC.

Step 2: Connect Samsung Galaxy S3 I9305 to PC via USB cord.

[Note: Before plugging the phone to the computer, be sure that you have installed USB driver software, if not, click HERE to download the firmware]

Step 3: Then, place Android 5.0.2 Lollipop zip file into the phone's SD card memory. [Note: Users are advised to paste the .zip file in SD card root, not in any other folder.]

[Note: Before installing the custom software, be sure that the device must have been rooted and has installed ClockworkMod Recovery tool.]

Step 4: Now, turn off the device and disconnect from the PC.

Step 5: Then perform the regular Recovery Mode sortie by press holding 'Volume (up)', 'Home' and 'Power' buttons.

Step 6: After entering the RECOVERY mode, clear the phone memory, by choosing 'wipe data/factory reset' option.

[Note: use 'Volume' keys to navigate and 'Power' button to select options, while operating under Recovery Mode.]

Step 7: Now, clear the cache memory by selecting 'wipe cache partition'.

Step 8: Then to go back to ClockworkMod recovery, and select 'advanced' and tap 'wipe dalvik cache' [Note: This step is optional, but many recommend this procedure so that user will not face boot loops or any other errors in the middle of custom ROM installation].

Step 9: Again come back to main recovery screen and then tap 'install zip from SD card'.

Step 10: Then tap 'choose zip from sdcard' and go to Android 5.0.2 ROM .zip file in SD card and enter the installation process. Repeat same process for Google Apps [Note: use 'Volume' keys to navigate and 'Power' button to select options].

Step 11: Once done with the installation process, navigate to '+++++Go Back+++++' and re-start the device by opting 'reboot system now' seen in the recovery menu.

Now, your device (Samsung Galaxy S3 I9305) will take a few minutes to complete the booting process.

Users then head to Settings >> select About phone to confirm the installation of CyanogenMod [Unofficial] Android 5.0.2 Lollipop CM12 Alpha custom ROM.

[Credits: XDA Developers Members - DerTeufel1980 and sbrissen]

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