For those who enjoy flashing custom ROMs and experimenting with kernels, here’s a useful tutorial on how you can backup EFS (IMEI and NVRAM) on Redmi 4X smartphone.

How to backup IMEI and NVRAM on Redmi 4X (santoni)

  1. Let’s start by connecting our Redmi 4X device to PC via USB cable.
  2. Open “Phone” application, call *#*#13491#*#*, tap on “DIAG,SERIAL_SMD,RMNET_BAM,ADB” press “OK”.
    • Make sure all drivers are installed correctly and your device is recognized as “Qualcomm HS-USB Diagnostics 9091” in device manager.
  3. Download and install QPST tool. Start it by opening the “QFIL.exe” file.
  4. Make sure your connected device is found as “Qualcomm HS-USB Diagnostics 9091” in QPST.
  5. In the top menu, press “Tools” and select “QCN Backup Restore”.
  6. Now in the opened window press “Backup QCN” to make EFS backup. In case you’ve got dual sim device, then enable “Enable Multi-SIM” option. To restore backed up .qcn file, repeat the same steps and use the “Restore QCN” button.

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