Let’s use Samfw.com as an example—it’s the most consistent free source.
Click each button in Odin and navigate to your extracted firmware folder: samsung galaxy j7 nxt firmware download work
BL_AP_ file (this takes longer to load—be patient)CP_ fileCSC_ (NOT HOME_CSC unless you want to keep data, but for a clean fix, use CSC to wipe)Do not check any extra boxes in Odin aside from Auto Reboot and F. Reset Time. Guide — Samsung Galaxy J7 NXT: Firmware Download