The first Lollipop update for the One Max comes from XDA recognised contributor and developer, Flyhalf205, in the form of unofficial CynogenMod 12.1 based Android 5.1 custom ROM.

Although the One Max has long been HTC's premium phablet featuring the flagship One M7's unibody aluminium design with power-packed hardware, the company seems far from releasing any Lollipop update for the handset and hence the CM12.1 ROM from XDA gains precedence.

The test builds of CM12.1 ROM are now available for a range of One Max variants including Global GSM, Sprint and Verizon Wireless.

The folks at Android Geeks have reportedly stated that the CM12.1 ROM is in its early stages of development and hence it may feature a few minor untested bugs or broken features such as random force closes or bugs with text messaging.

As this ROM is entirely based on the original Android Open Source Project (AOSP), it is necessary to unlock your phone's bootloader before installing the Android 5.1 CyanogenMod 12.1 ROM.

Interested users who wish to try out the stock-like Lollipop experience on their smartphone may go ahead and install the highly-stable unofficial CM12.1 ROM for HTC One Max, using the step-by-step guide posted below.

IBTimes UK reminds readers that it will not be held liable for any damage to device during or after the ROM installation. Users are advised to proceed at their own risk.

Downloads Required

Unofficial CyanogenMod 12.1 ROM for HTC One Max

Android 5.1 Google Apps

Stepsto InstallAndroid5.1 Lollipop on HTC One Max via unofficial CyanogenMod 12.1 ROM

  1. Ensure that your device is HTC One Max by verifying the device model number via Settings> About Phone. Do NOT flash this ROM on any other device as it may inadvertently brick or damage the device.
  2. Copy the CM12.1 ROM file "" and Gapps package file"" to the device's internal storage and remember the location where you save it.
  3. Install a custom recovery (TWRP, CWM, etc) on your device.
  4. Boot into Recovery mode via adb or hardware buttons or use the QuickBoot app if your device is rooted.
  5. In recovery mode, back up data on your current ROM. If using TWRP, select Backup and perform a Swipe to Back Up from the bottom of the screen.
  6. Then select Wipe and do a Swipe to Factory Reset from the bottom of the screen.
  7. Return to the main menu of TWRP recovery and select Install.
  8. Browse to the file where you saved the CM12 ROM zip file, select it and Swipe to Confirm Flash on the bottom of the screen. Now, wait until the flashing process completes.
  9. After the ROM is flashed, repeat step 8 to flash the Gapps package as well.

10.Once both the files are flashed, return to recovery's Main menu and select Reboot > System.

[Source: Android Geeks]