Sprint variant of the Samsung Galaxy S3 can now be upgraded to the latest CyanogenMod 10.1 M-Series build, a custom ROM official from CM team and which is more stable than the Nightly version of CM 10.1. Read the entire post and you will learn how to successfully flash this new Android 4.2.1-based OS for your SGS3 Sprint phone.
It is a guide for power-users that want to change and test as many ROMs as possible. It is based on stock Android 4.2.1 and it packs all CyanogenMod functions and features. If you’re a fan of CM10.1 Nightly builds, then you will find out that this is a much more stable release and in order to correctly install it, you will need to read the preparation guide below.
Here’s what you need to know before installing CM 10.1 M1 custom ROM on Sprint Samsung Galaxy S3:
Install the new OS only for the Sprint variant of Samsung Galaxy S3 model number L710. It won’t work for any any other version of SGS3.
The phone needs to be on an unlocked bootloader, it has to be rooted and running a custom Recovery image such as TWRP or CWM Recovery.
Use the custom Recovery mode to create a full NANDROID backup of your currently installed ROM. This sets a restore file for your phone, just in case something goes wrong and the new ROM is unable to boot.
Use this guide here to learn how to successfully sync your Gmail account with your Contacts data.
Charge the device’s battery so that it won’t power off during the installation of this new ROM.
This is a guide for advanced users and you shouldn’t blame us in case something goes wrong. Nor in case you lose any important data in the process. Make sure to read the entire post and don’t skip any actions listed below.
If you can’t complete the installation, then you should ask for more help in comments.
These were all the extra steps that you had to go over before moving to the most interesting part of this post.
Devices that are already sporting a CM10.1-based ROM can skip the ‘Factory Reset’ step and install the new M1 build of CyanogenMod 10.1 over the previous version. If you’re unsure about this, then it would be better for you to factory reset the device.
How to flash CM10.1 M1 custom ROM for Samsung Galaxy S3 Sprint L710:
Download the CyanogenMod 10.1 M1-build ROM HERE. Don’t unzip and save the file on your PC.
Get the Gapps for CM10.1 from HERE. This is the file that you need to flash in order to get the full Android 4.2.1 Jelly Bean experience. Don’t unzip.
Connect the smartphone to computer and then move the downloaded files on its internal SD card. Unplug the phone from PC when the files are successfully moved.
Power off your smartphone and after that you need to boot it into custom Recovery Mode. Do it by pressing at the same time Volume Up, Home and Power. Release the buttons only when the CWM or TWRP Recovery mode appears.
Create a full NANDROID backup if you didn’t have one already created. Select ‘backup and restore’ for CWM or, press ‘backup’ for TWRP. Create it and then get to the next step. NOTE: If you already have a backup or you don’t want to make one, then you can skip this step.
Select ‘wipe data/ factory reset’ Confirm this process and then you can continue with the rest of the process. NOTE: If your device runs already on a CM10.1 ROM then you can skip this step.
Now, select ‘install zip from SDcard’ and then ‘choose zip from sdcard’. Find the CM10.1 M1 ROM and confirm its installation.
After the ROM installs you should select again the ‘choose zip from SDcard’. But, now you have to flash the Gapps for CM10.1 zip file. Confirm the install and then get to the next step.
Select ‘Go Back’ option and you’ll return to the main Recovery menu.
Choose ‘reboot system now’. Wait until the first boot process completes to load all new files, as it shouldn’t take more than 5 minutes to complete.
Enter your Google Account details when you’re shown the welcoming screen of the new CyanogenMod 10.1 / Android 4.2.1 custom ROM.
Test all of its features and that should be all.
NOTE: if the first boot process takes too long to complete or, in case the device gets into a boot loop, then you will have to power it off by removing its battery. Re-insert the battery after 5 seconds are passed and then repeat the entire tutorial once again.
In case you find this new CM10.1 MR1 release unstable, then you should restore your device to the previous ROM using the custom Recovery mode to restore the NANDROID backup. In case you have any other questions, leave them in the comments section below.