How to downgrade to 4.1.1 from 4.3 Galaxy S3 SGH-I747M

Hi, a month ago I did something wrong with my Galaxy S3 SGH-I747M for not read here before do an upgrade that the new bootloader are locked and have a new counter called Knox but I upgrade to 4.3 from Rogers because I don't want to wait for the official 4.3 Claro Network, then I want to downgrade but Odin FAIL Oh noooo and trip the new counter to 1, when I knew what the problem was, I do a mixed Rom and works Very good on Claro Puerto Rico Network and I want to share my knowledge and what I do to this Model of S3 variation, I want to help and to be helped too. Just follow this simple instruction:

JUST FOR GALAXY SGH-I747M DEVICES

I don’t know if works with other variant of S3 or Samsung Devices.

I want to Share the way to downgrade your S3 Canadian Version to previous version, I do it with 4.1.1 no network or Wi-Fi problems, and you don’t need any patch for this.

1- From Sammobile download your Rom 4.3 JB version.
2- From Sammobile download your Rom 4.1.1 JB version.
3- Download Odin307.zip and extract.
4- Only Windows users, download this program and install it Cygwin.
5- To extract Tar file you need 7zip or Winrar, then extract from 4.3 JB the following file: NON-HLOS.bin. I know you’re asking why NON-HLOS.bin, because this is the modem and network file and the 4.3 bootloader installed in you’re phone don’t work with the older, we need the newer from 4.3 for the phone works correctly.

6- Extract from 4.1.1 JB all the files except aboot.mbn and NON-HLOS.bin.
7- Go to C:/cygwin/home/'win_user_name' just cut & paste all the extracted file there without making any folder.

8- Open Cygwin Terminal cut & paste the following codes:

First Code:
tar -H ustar -c boot.img cache.img.ext4 NON-HLOS.bin recovery.img rpm.mbn sbl2.mbn sbl3.mbn system.img.ext4 tz.mbn > S3ModedRom.tar

When Finish

Second Code:
md5sum -t S3ModedRom.tar >> S3ModedRom.tar

Then

Third Code:
mv S3ModedRom.tar S3ModedRom.tar.md5

9- Run Odin, go to PDA bottom and Find new Rom called S3ModedRom.tar.md5.
10-Restart you’re Phone and after it vibrate press Volume Down + Menu Button will show Download Mode press volume up and connect your device through usb cable to PC.
11- On Odin Hit start, when it’s complete and say PASS you’re done!!

If this helps please hit Thanks :good:

It has been suggested that downgrading stock 4.3 ROM to stock 4.1.1 may be possible as long as there is no attempt to downgrade the 4.3 bootloader otherwise, this would result in a brick. The good news is that I was able to successfully downgrade from 4.3 to 4.1.1 on my i747 (AT&T) without ending in a brick by flashing with Mobile Odin. Although it initially appeared to get stuck in reboot, booting into recovery and doing a reset worked and the phone is now running fine on 4.1.1. The bad news, however, is that going this route for the purpose of free unlock may not work as the hidden menu appears unsupported. After typing in *#197328640# in the dial pad, ServiceMode popped up but the usual menu items didn't show and the screen was otherwise blank. All other normal functions of the phone appear to be OK.

Has anyone else tried this or could there be something I didn't do right?

---------- Post added at 03:19 PM ---------- Previous post was at 03:13 PM ----------

audit13 said:

I have unlocked three phones (all of them were i747m ) using the free method but none of them had been upgraded to 4.3 so we'll have to wait for someone to try using the free unlock method on a phone that is running a 4.1.1 ROM with a 4.3 bootloader.

Click to expand...

Click to collapse

Looks like that was what I answered in my last post. The downgrading from 4.3 ROM to 4.1.1. ROM without altering the 4.3 bootloader is possible. I just did it by flashing with Mobile Odin and my i747 AT&T is still running fine on 4.1.1. The free unlock didn't work, however, as the hidden menu appears unsupported. When I entered the code to the hidden menu, all I had was a blank screen.

NV files and IMEI Restore

To let you know, besides having the problem for upgrade from 4.1.1 to the version 4.3 and then downgrade to the previous version apparently I deleted with the CWM-Recovery the EFS folder and NV files, but I had read a post about it and it worked, of course this is for the one who wipes these files, but since I had made a backup of the EFS folder, so what I needed was to rewrite the NV files, but I did not have a backup of my NV Files and now WHAT, but thanks to God my wife has the same phone and I copy their NV Files and everything worked fine following the steps here: (FIX)(SOLVED) Deleted or Injected IMEI and No signal or stock on Edge :good::highfive:

??

Does this work for i747 att? I mean doing this file change with the 4.3 att to 4.1.1 att..

Yes, trying to downgrade to 4.1.1, assuming you get past the Odin bootloader check, could hard brick the phone.