Enable Developer Options (tap Build Number 7 times). Step 2: Enable USB Debugging and OEM Unlocking. Step 3: Open QPST Configuration tool on your PC. Step 4: Click on "Backup" tab. Step 5: Select your OnePlus 7T Pro port (usually COM). Step 6: Save the file as oneplus7tpro_original.qcn .

→ Click Restore QCN .

This occurs if your EFS partition is completely locked or blocked. You may need to use TWRP or an ADB shell to manually wipe/reset your corrupted EFS ( modemst1 , modemst2 , and fsg partitions) before QFIL can write the new data.

The Ultimate Guide to OnePlus 7T Pro QCN Files: Repairing Network and IMEI Issues

Most Qualcomm diagnostic tools require a Windows environment.

Launch a QCN IMEI converter tool or use a Hex Editor to locate the hex values corresponding to the placeholder IMEI in the downloaded file.

Reboot your device. Your IMEI will temporarily show as null or zero; this is expected. Step 5: Restore the Rebuilt QCN File Re-enable using the command from Step 1. Open the QPST Software Download tool again. Navigate to the Restore tab.

If you're here, you've likely already lost your IMEI or have a radio issue. Restoring a QCN file can bring your phone back from the dead.

Navigating to Settings > About Phone reveals "Baseband: Unknown." This indicates that the modem firmware cannot communicate with the hardware because the NV (Non-Volatile) items stored in the EFS partition are missing.