Working with QCN files is a high-level technical task. Using an incompatible QCN file from a different model can result in a or a "Hard Brick" state. Always verify that the file version matches your device's baseband version exactly. To help you get the best results, could you tell me: What model of phone are you trying to repair?
It is a portable tool, often distributed in a .zip file. tungtata qcn toolzip install