CM 12.1 Stable builds are now live for all the Sprint HTC One Max devices. Check the info in this post if you want to learn how to successfully update your phone with a brand new custom ROM.

The CM 12.1 ROMs are based on the AOSP Android 5.1.1 Lollipop builds. Since this is a stable release you should be getting one of the best Lollipop OS environments as well as tons of extra features designed by the CyanogenMod team. Read the following guidelines before starting the updating process:

  • use this post only with the Sprint HTC One Max devices.
    - you shouldn't attempt to flash the files you find in this article on any different HTC One Max devices.
  • your phone's firmware has to be rooted and running a custom Recovery image like CWM or TWRP versions.
    - the installed custom Recovery needs to be updated to its latest version, so that it supports the latest Android 5.1.1 custom ROM installations.
  • in the tutorial you can find two extra important steps: the NANDROID Backup and the Factory Reset ones.
    - the NANDROID Backup creates a complete copy of the ROM that's already installed on your device, one that you can use in case the new CM 12.1 ROM doesn't boot in normal mode.
    - with that particular backup you can repair your device in case the CM 12.1 refuses to boot after you complete the installation.
    - the 'factory reset' step will remove the old ROM and allow the new ROM to boot successfully in normal mode.
    - factory resetting the device won't remove any data from internal storage, as the system partition is the only one that's going to be deleted in the process.
  • if you want to save data from installed apps, then you can use the Helium tool for Android.
    - Contacts info can be synced with your default Gmail account.
  • check the battery charge of your phone and make sure that there is at least 50% left before it completely discharges.
  • this tutorial is destined to be used by advanced users only.
    - we cannot be held responsible in case you brick your device nor in case you lose any data in the process.

You can continue to install future CM 12.1 Stable ROM files using the CyanogenMod Updates menu under Settings> About Phone menu.

How to flash CM 12.1 Android 5.1.1 Stable ROM for Sprint HTC One Max:

  1. Download the CM 12.1 SNAPSHOT zip file from here.
  2. Download Gapps for Android 5.1.1 ROMs from here.
  3. Transfer both zip files on to your phone's internal storage.
    - make sure not to unzip the archived files.
    - disconnect the device from PC after all the files are copied successfully.
  4. Switch off your phone.
  5. Now boot it in Custom Recovery Mode.
  6. First you need to create the NANDROID Backup for the installed ROM:
    - CWM: select 'backup and restore' option.
    - for TWRP select 'backup'.
    - set a name for the file and confirm process.
  7. Now you can 'factory reset' the device:
    - CWM: select 'wipe data/ factory reset'.
    - TWRP: select 'wipe' options.
    - confirm the factory reset and continue to the next step when done.
  8. Start the CM 12.1 Stable installation:
    - CWM: select 'install zip from sdcard', then 'choose zip from sdcard'.
    - TWRP: select 'install' option.
  9. Find the CM 12.1 Stable zip and confirm the flashing process.
    - do not press any buttons until the new ROM is done installing.
  10. When the CM 12.1 SNAPSHOT file is done you can flash the Gapps zip in the same way.
  11. Reboot your phone in normal mode after all files are flashed successfully.

Note that the first boot process of this new ROM is going to take a while before it loads all the new files.

If the first installation attempt fails to complete, then you can retry the whole guide more than once. Make sure not to skip any steps and that your phone meets all requirements listed above the tutorial before repeating installation.

If you need any extra help completing this guide, then you should use the comments field below.

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