Question: how to backup qcn file?
Answer: Steps to Backup QCN/EFS on Qualcomm devices Download the QPST package and run “QFIL.exe” file. Make sure that the program is in “Lenovo HS-USB Diagnostics” mode. Note: By default, the backup QCN file with the name of “00000000. qcn” will be saved to “C: \ temp \”.