A complete "4-file" (Service Firmware) package usually includes: Contains the device's bootloader files. AP (System): The main system partition and core OS. CP (Modem): Handles radio and connectivity.
Check your current binary in Download Mode (look for "RP SWREV: B:2"). You cannot downgrade from U2 to U1.
When the warning screen appears, press to confirm. Connect your phone to a PC using a reliable USB cable. ⚠️ Critical Reminders
Ensure you have the Samsung USB Drivers installed on your computer so Odin recognizes the device. If you'd like, I can help you: Find the latest Odin version for your PC