| Error Message | Likely Cause | Solution | |---------------|--------------|----------| | “Protocol error (no handshake)” | USB cable or driver issue | Use original Samsung cable. Reinstall drivers. | | “Auth (hash) mismatch” | Bootloader version mismatch | The firmware is older than your current bootloader. Download a newer firmware. | | “Secure Check Fail: super” | Corrupted super partition | Use the “Home CSC” instead of regular CSC, or check “EFTsU Ignore Secure Check” option. | | “Only official released binaries” | OEM unlocking not done | Go back to developer options; toggle “OEM Unlock”. Wait 7 days if it’s grayed out. |
The developer maintains a Telegram channel named @eftsu_official (always verify the handle – fakes exist). Inside the pinned messages, you will find a direct link to with MD5 checksum. eftsu flash tool v6 download
Once everything is set, start the flashing process. The tool will guide you through the steps, and your device will restart during the process. | Error Message | Likely Cause | Solution
: It is built to flash files in the .8EFT format, which are official custom files from the EFT team. Download a newer firmware