A third-party operating system built by independent developers (such as LineageOS or Resurrection Remix). These ROMs often offer newer Android versions than what HTC officially released for the X9, alongside advanced customization options. Android System Partitions
Firmware updates are usually safe, but it is always best to back up your photos, contacts, and important files just in case.
Boot the phone into (Power off, then hold Volume Down + Power ).
Boot to bootloader and select "Factory Reset." This wipes data but often resolves incompatibility between old data and new firmware drivers. Firmware Change Update on HTC One X9
The of your HTC One X9 (e.g., European, Asian Dual-SIM).
An RUU is the official, all-in-one software package provided by HTC for restoring a device to its factory state.
Check the boxes for , then swipe the slider at the bottom to clear the partitions. Boot the phone into (Power off, then hold
If your OS number ends with a low build (e.g., 1.18.x), you are several firmware revisions behind. The final official firmware for most HTC One X9 variants was around version 2.18.x, depending on the region (Taiwan, India, Europe, or Middle East).
If your phone is stuck in a boot loop or the OTA fails, the official HTC ROM Update Utility (RUU) is the best recovery tool. Steps to Follow:
Turn off your phone. Press and hold Volume Down + Power to enter the bootloader. Select FASTBOOT . Connect to PC: Plug your phone into your computer. An RUU is the official, all-in-one software package
If your version-main is older than 2.18.709.5 (for Taiwan/Asia) or 2.18.401.5 (for Europe), you are due for a firmware change update.
Even with precise steps, things go wrong. Here’s how to troubleshoot: