If you want that step-by-step guide, say “Yes — backup/restore guide” and include your exact model number (e.g., 2201117SG) and OS state (rooted/unrooted), and whether you’re on Windows or Linux.
| Symptom | Cause | |---------|-------| | No mobile network / No service | Corrupted IMEI or null baseband | | IMEI shows as 0 or N/A | QCN partition overwritten or wiped | | Wi-Fi MAC address changes every reboot | EFS data mismatch | | Unable to lock 4G band | Calibration data missing | | After a failed custom ROM flash | ROM overwrote modemst1/modemst2 | | After using a “reset network settings” method | Erased QCN by accident | redmi note 11 464 4g xqcn qcn efs file hot free do