How can I downgrade my OS?

[LuminaryLion]

Problem downgrading version with Odin

Hello everyone

I am new on this forum and I have been looking here and there alot to find out my problem, but still could not figure out what to do.

Let me explain what I aim to do:
I want to downgrade my Samsung Galaxy S3 (SGH-I747M) with Telus from version 4.4.1 to 4.1.1 in ordor to be able to unlock my device.

Running on Odin3_v.185 (Also tried on Odin3_v3.04)

So, I boot my device into Download/Odin Mode;
Connect it to my computer using USB port;
(Previously downloaded Samsung Galaxy S3 Drivers) Odin sees my Device;
I add the PDA file;
Uncheck "Auto Reboot";
Press start then:

<ID:0/003> Added!!
<OSM> Enter CS for MD5..
<OSM> Check MD5.. Do not unplug the cable..
<OSM> Please wait..
<OSM> KIES_HOME_I747MUMBLL1_I747MPCTBLL1_688429_REV04_user_low_ship.tar.md5 is valid.
<OSM> Checking MD5 finished Sucessfully..
<OSM> Leave CS..
<ID:0/003> Odin v.3 engine (ID:3)..
<ID:0/003> File analysis..
<ID:0/003> SetupConnection..
<ID:0/003> Initialzation..
<ID:0/003> Get PIT for mapping..
<ID:0/003> Firmware update start..
<ID:0/003> sbl2.mbn
<ID:0/003> NAND Write Start!!
<ID:0/003> sbl3.mbn
<ID:0/003> aboot.mbn
<ID:0/003>
<ID:0/003> Complete(Write) operation failed.
<OSM> All threads completed. (succeed 0 / failed 1)

I don't know if I missed something or my .md5 file is wrong (which I downloaded a second version with same result)...

Any help will be much appreciated!!

Thank you,

LuminaryLion

 

[Golfdriver97]

Re: Problem downgrading version with Odin

Welcome to the forums.

from version 4.4.1 to 4.1.1

That is the issue, the problem, and why it is failing. Samsung included a security protocol called Knox in the 4.3 bootloader. Once you took that update, you cannot roll back beyond that.

 

[Rukbat]

Re: Problem downgrading version with Odin

Once you're at 4.4, you can't even flash 4.3. (It's not Knox that;s doing it, it's a bank of "software fuses", and 4.4 is set to 3 IIRC, while it has to be set to 2 to flash 4.3. And it's a "write once" kind of thing - once it changes from 2 to 3, the only way to change it back is to put in a motherboard that's got the fuses set the way you want.)

And you wonder - no, maybe you don't - why so many people are looking for alternatives to Samsung for their next phone.