On Htc One X9 — Firmware Change Update

He had ignored the last three updates. But this one was different. The changelog read: “Critical: Baseband firmware revision for VoLTE compatibility. Network carriers will phase out 3G fallback in 60 days.”

buttons simultaneously. From this menu, users can initiate a system update that reads the firmware directly from the external card. HTC One X9 - Updating your phone's software Firmware Change Update on HTC One X9

When the operating system becomes corrupted or a user wishes to revert to a previous factory state, "flashing" a ROM Upgrade Utility (RUU) becomes necessary. This process is more technical and carries inherent risks. HTC One X9 - Updating your phone's software He had ignored the last three updates

Updated power management firmware improves charging curves. Users report that after the final firmware update, the One X9 charges 20% faster on a 2A charger and no longer throttles charging when the screen is on. Network carriers will phase out 3G fallback in 60 days