If you are looking to restore your to its factory state or simply want the official Ice Cream Sandwich (ICS) experience for the Taiwan/Asia region, the official RUU is the most reliable method.
This is specifically for the Asia/Taiwan GSM GSM model. Do not use this on US CDMA versions (Sprint/Virgin Mobile). Rooting: Installing this RUU will remove root access. Bootloader: Your bootloader may be automatically relocked.
Because an RUU modifies the deepest levels of your smartphone's storage, skipping preparation steps can permanently ruin or "brick" your hardware. If you are looking to restore your to
The RUU file might be corrupted or modified. Solution: Redownload the file from a trusted source (preferably HTC’s official support site or a reputable HTC community such as XDA Developers). Verify the SHA‑1 checksum if available.
Official RUUs generally require a locked or relocked bootloader if the device is in an "S-ON" (Security On) state. If a device has been modified with custom recoveries, you must issue the command fastboot oem lock via the Android Debug Bridge (ADB) before running the executable. CID and MID Validation Rooting: Installing this RUU will remove root access
: The utility lost contact with the phone. Swap USB ports, change the cable, or reinstall the HTC USB drivers.
: The phone must have a Taiwanese CID ( HTC__621 ) or have Security set to Off ( S-OFF ). Execution Steps The RUU file might be corrupted or modified
270747 is the internal compilation changelist number from HTC’s build servers. Signed means the software contains HTC’s official cryptographic signatures, allowing it to pass secure boot verification on locked bootloaders. Key Technical Specifications of the Update