How to Downgrade Samsung Galaxy S20 FE Software Safely with Odin

Understanding Software Downgrade Limitations

• 💡 The primary limitation for downgrading software on a Samsung Galaxy S20 FE is the bootloader version.
• 📌 You cannot downgrade your system below the current bootloader version, indicated by a letter (e.g., H) in the baseband version.
• ⚠️ Attempting to flash an older firmware than the current bootloader version will result in an 'SW REVISION CHECK FAIL' error.

Finding and Downloading Compatible Firmware

• 🔍 To find firmware, search for your model number (e.g., G781B) and desired region or carrier code (e.g., OPV, XCO).
• 🎯 Websites like SamFW are recommended for fast downloads of firmware versions.
• ⚠️ Firmware versions are listed chronologically, starting with numbers (1, 2, 3...) and then letters (A, B, C...), so ensure the downloaded version is current or newer than your bootloader's letter.

Preparing Tools and Files

• 🛠️ You will need to download Samsung USB drivers and the Odin flashing tool (latest version recommended).
• 💻 Install the Samsung drivers and extract the Odin tool to a dedicated folder.
• 📂 Extract the downloaded firmware file, which will contain multiple files (BL, AP, CP, CSC) for flashing.

Entering Download Mode and Flashing

• 🔌 To enter Download Mode, power off the phone, then press and hold Volume Up + Volume Down simultaneously while connecting it to your computer via USB.
• ⚠️ Confirm by briefly pressing Volume Up on the warning screen.
• 💻 Open Odin, connect your phone (it should appear as an ID:COM port), and load the corresponding firmware files (BL, AP, CP, CSC) into their respective slots in Odin.

Completing the Downgrade Process

• ✅ Click 'Start' in Odin to begin the flashing process. If the correct firmware version is used, it should not fail.
• 📈 A progress bar in Odin indicates the flashing is working, and the phone will restart automatically upon completion.
• 📱 After the phone restarts, it will be running the downgraded firmware and will require initial setup.