- Confirm that your device is HTC One M7 AT&T, GSM, and T-Mobile models m7_u, m7_ul, m7_tmo, and m7_att. No other variant or model should be tried, otherwise the device will be bricked. To check you model device, on the Settings menu, tap on About phone and you will see the model number.
- Check that your device is rooted; Install a Clockwork Mod Recovery or TWRP as you may need to wipe data on your device.
- Install the right USB drivers on your PC to make your device recognizable.
- To avoid interruption of the installation process, have at least 80% battery power.
- Properly follow this steps to install the custom CyanogenMod CM13 Android Marshmallow ROM on the HTC One M7:
- Start by downloading the CyanogenMod CM13 custom Android v.6.0 Marshmallow ROM then the Google Apps onto your computer
- Plug in your HTC One M7 to the computer using a USB cable
- Save the downloaded Custom ROM and Google zip files in the microSD root folder and nowhere else.
- In the android-sdk-windowplatform-tools directory, save the boot.img file
- Switch off your HTC M7 then unplug it from the computer.
- Hold down the Volume Down and Power keys together to turn your device to the Bootloader mode.
- Once on your HTC One M8 is on Bootloader mode; on your computer, navigate to the android-sdk-windowplatform-tools directory, then click Shift then right-click to launch a Command prompt.
- Input ‘fastboot flash boot boot.img’ then enter. Thereafter, type in ‘fastboot reboot’ and click Enter. Follow the steps that appear on the screen. Afterwards, tap on the bootloader menu and select Recovery Mode.
- On the Recovery Mode, do a factory reset or otherwise wipe the data on your device. You can select these options on the Recovery Menu by using the Volume button to scroll and the Power key to confirm.
- Tap on wipe cache partition to clear cache.
- To avoid errors e.g boot loops during the ROM installation process, go to the ClockworkMod recovery you installed and tap the advanced option then select wipe dalvik cache.
- Navigate to the recovery screen and the select install zip from SDcard.
- Select the choose zip from sdcard option then scroll to the downloaded custom ROM zip file and start the installation process. Repeat the same steps with Google Apps file.
- On installation finish, return to the main recovery menu and select reboot system now to restart the HTC One M8.
HTC One M7 was last updated with Android 5.0.2 Lollipop early this year. The good news is that a new CyanogenMod CM13 custom ROM based on Android v6.0 Marshmallow has been released for HTC One M7. However, the CM13 firmware is still at its experimental stages thus it may have some slight bugs but it still offers Android 6.0 intuitive features. Those interested in downloading it should exercise caution, as the procedure is technical and should be done by someone with rooting knowledge specifically for Android devices.
What's my model number?
There are several ways to locate your model number:
- Option 1
- On your device, go to Settings, then "About device" and scroll down to "Model number"
- Option 2
- Often times you can view the model number inside the device, by removing the battery
- Option 3
- Using Samsung's model/serial number location tool