The SM-G920F (Samsung Galaxy S6) is a critical partition containing the device's Non-Volatile information, such as IMEI, baseband, and network calibration data. When this file is corrupted or missing—often after a bad firmware flash—it leads to the "long story" of a phone that won't connect to a network or shows "IMEI Unknown". Why NV Data Fails
NV stands for . Unlike RAM (which clears when the power is off), NV memory retains data even when the battery is removed. On your Samsung SM-G920F, the NV Data partition stores the unique, device-specific configuration of the modem and radio hardware. sm-g920f nv data file