Download Complete. Do not disconnect for 30 seconds.Success indicator: The phone reboots into Download Mode automatically. You can now flash stock firmware via Odin.
Cause: You are trying to flash an older loader (downgrade). Samsung A20s has anti-rollback (RMM/KG).
Solution: You must flash the same or newer binary version. Check the 5th digit from the end in your firmware (e.g., A207FXXU4... – the 4 is the binary version).
Before downloading files, you must understand what the "loader" actually is. The Samsung A20s uses a tiered boot process:
The "loader file full" inside an Odin package usually contains sboot.bin, cm.bin, tz.mbn, hyp.mbn, devcfg.mbn, and sec.dat.
After flashing a combination file for FRP unlock, the phone refuses to boot into the normal system. The loader becomes mismatched with the newer bootloader version.
If the original eMMC is physically damaged (short, high current draw), replace it with a pre-flashed eMMC containing the correct loader. Services like eMMC-Repair offer pre-programmed chips for the A20s.
No. The partition map and authentication keys are completely different. You will cause a pre-boot authentication fatal error.
