Example repair: For a Samsung with “IMEI null”, you can use the File Manager to replace the corrupted /efs/nv_data.bin with a backed‑up copy, bypassing the need for a full firmware flash.
: Use the Shell or the EFM support page to grab the latest eMMC File Manager exe. Downloads - Easy JTAG Plus z3x easy jtag emmc file manager 122 download updated