I got a notification for a newer version of Android available for my mobile. So I just downloaded and installed it. Everything was fine until I saw my screen was freezing. Home and back buttons worked but when you touched the screen nothing happens. I had to lock and unlock the screen to use my phone for seconds then it froze again. This happened in some last updates , then I used Wipe Cache Partition and the problem was gone.

But this time, I used WCP and nothing happened. You can see on the image below.


So, I decided to download the previous firmware and Android 6 & 7 firmware from Sammobile and install it using Odin. I am sure that these firmwares are for my phone , I checked everything. but then I see a "complete(write) operation failed" error and FAIL! in Odin for all the firmwares. after seeing this error I try for a second time , but then it just keep showing me the Setup Connection and nothing happens. Any ideas ?


  • I have answered a similar question. Samsung utilitizes something called rollback protection fuses. This prevents flashing older version or downgrade of firmware. The fatal error you received when attempting to flash though odin probably looked like: SW REV. CHECK FAIL(BOOTLOADER) DEVICE: 3, BINARY: 1 a breakdown of the error is your Device: bootloader is version 3 your binary (the file your flashing): bootloader is version 1. The flashing process fails of trying to install an older bootloader. android.stackexchange.com/a/205906/116800 – Bo Lawson Jan 19 '19 at 15:30
  • @BoLawson so you're saying that it's not possible downgrading from a December firmware to a September firmware , even if both are android 8 ? – KYWH Jan 19 '19 at 15:43
  • I was mostly commenting the previous firmware android 6 and 7. However, it is possible to downgrade a December to a September firmware if they are are both android 8 unless the bootloader was version changed in the update. You can tell by looking at the version number pda. Look for either a U or an S with a number next to it that is the bootloader version. Example: pda: A720FXXU6CRJ7 the U6 is the bootloader version if its lower than the current firmware on the device then it will fail with the error: SW REV. CHECK FAIL(BOOTLOADER) DEVICE: 6, BINARY: 5. – Bo Lawson Jan 19 '19 at 16:15

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