Experts strongly recommend backing up any existing EFS or QCN data before proceeding, as writing the wrong file can permanently damage the device's radio functions.
Using a tool like QFIL , the user selects the "fixed" QCN file and "Restores" it to the device. Download Y12a fixed qcn
Since QCN files often contain the IMEI of the donor device, technicians must usually use an IMEI repair tool to change the numbers back to the original ones found on the phone's sticker or box to ensure legality and network compatibility. Expert Consensus Experts strongly recommend backing up any existing EFS