Originally Posted by DrRodion
Hey guys this is my first post here and I am in need of some help. I have rooted several phones in the past with no trouble before my galaxy s4. I was trying to downgrade my s4 so I could root but managed to soft brick my phone in the process. Trying to turn on my phone I encounter and error saying "Firmware upgrade encountered an issue. Please select recovery mode in Kies & try again". I have tried various methods I have found on the forums. Trying to recover firmware in Kies I get an error saying "Firmware Update encountered an unexpected error". Whenever I try to flash anything in odin I get an error.
<OSM> Enter CS for MD5..
<OSM> Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> I337UCUAMDB_I337ATTAMDB_I337UCUAMDB_HOME.tar.md5 is valid.
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/004> Odin v.3 engine (ID:4)..
<ID:0/004> File analysis..
<ID:0/004> Get PIT for mapping..
<ID:0/004> Firmware update start..
<ID:0/004> NAND Write Start!!
<ID:0/004> FAIL! (Auth)
<ID:0/004> Complete(Write) operation failed.
<OSM> All threads completed. (succeed 0 / failed 1)
I don't really know what else I can try. My goal is to try to get back to stock.
As jd said, you need to flash the firmware you were on before. MDL and MF3 are other 4.2.2 firmwares, MK2 is the 4.3 firmware, and NB1 is the 4.4.2 firmware. Unless you've had your phone since around launch and never taken an update, you're probably at least on MF3.