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

Samsung has already discontinued software update service to Galaxy S3 series way back in 2014.

But, users of Galaxy S3 can still get the new firmware and stay up to date with custom ROMs available in Internet. Most popular among them is the crowd sourced CyanogenMod.

Prolific XDA Developer Forum member who goes by the moniker, matrixzone has released Android Marshmallow based CyanogenMod CM13 series custom ROM to Galaxy S3 AT&T model.

Also read: Google Android 6.0 Marshmallow: 7 key features you need to know

We also like remind our readers that this custom ROM is an experimental version, so there are some bugs in it. Galaxy S3 AT&T users are advised to exercise some caution before going forward with the firmware installation.

Prerequisites (things to remember before installing Custom ROM):

  • This new CyanogenMod [Unofficial] Android 6.0 CM13 Marshmallow firmware has to be installed on the Samsung Galaxy S3 (SGH-I747) AT&T models 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 Clockwork Mod (CWM) Recovery/ TWRP in the smartphone.
  • Users make sure they have installed USB drivers on the PC, or else your smartphone (Samsung Galaxy S3 AT&T) will not be recognized by the computer.
  • Make sure your device has more than 80 percent battery, or else there is chance of smartphone getting temporarily bricked if the installation process is interrupted in the mid-way.
  • 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. IBTimes India 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 procedure of CyanogenMod [Unofficial] Android 6.0 CM13 Marshmallow firmware on Samsung Galaxy S3 (SGH-I747) AT& T-

Step 1: Download CyanogenMod [Unofficial] Android 6.0 Marshmallow CM13 firmware (HERE) and Google Apps (HERE) in to your PC.

Step 2: Connect Samsung Galaxy S3 AT&T 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: Place Android Marshmallow zip file and Google Apps .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: Turn off the device and disconnect from the PC.

Step 5: 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: Clear the cache memory by selecting 'wipe cache partition'

Step 8: Come 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: Navigate 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 Marshmallow ROM .zip file in SD card and enter the installation process. Repeat the same procedure to install 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 AT& T) will take at a few minutes to complete the booting process.

Users then head to Settings >> select 'About phone' to confirm the installation of CyanogenMod [Unofficial] CM13 Android 6.0 Marshmallow firmware.

[Note: If faced with any other issues, please drop-in your concerns, HERE]

[Credits: XDA Developer Forum, CyanogenMod, matrixzone]