Redmi S2 Imei null solution, Nv data coruupt solution. Before you do this operation you must watch the video two or three times for understanding if any fail during the process your Device go to dead mode . First download the Qcn file or read by any working device.Then modify the Qcn file by qcn editor and save .Further write the Qcn file by any professional tool or use Qualcomm qcn tool its free version for read and write qcn data.after write do not reboot your device go edl mode and flash with appropriate file as mentioned the video . if you reboot your device nv data are corrupted and you can’t boot your device normally. Any doubt ask first then do it right.