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Can you downgrade bootloader?

OP xXFl4sh

10th January 2014, 09:47 PM   |  #1  
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I am thinking to flash a 4.4 ROM on my S3 I747M. The only thing I am worried about the bootloader. If I flash the latest boot loader can I downgrade it?

Here a scenario

I am on 4.4 kitkat,with the latest bootloader,and I decide to go back to 4.2.2 with the latest bootloader. Is it possible to do that?
11th January 2014, 01:56 AM   |  #2  
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Quote:
Originally Posted by xXFl4sh

I am thinking to flash a 4.4 ROM on my S3 I747M. The only thing I am worried about the bootloader. If I flash the latest boot loader can I downgrade it?

Here a scenario

I am on 4.4 kitkat,with the latest bootloader,and I decide to go back to 4.2.2 with the latest bootloader. Is it possible to do that?

What carrier do you use? If AT&T is it the MJB bootloader.

You can check what bootloader you having using this - https://play.google.com/store/apps/d...s.root_checker

If you are on AT&T with the MJB bootloader you CANNOT downgrade the bootloader. It will brick the phone. My guess is that you could possible run a 4.2.2 ROM with the MJB bootloader. I have run 4.3 and 4.4 on the MG2 bootloader with no problem but haven't tried to run a 4.2.2 on the MJB bootloader. As long as the 4.2.2 ROM doesn't flash a bootloader, I would try it. But that's me. Just back sure to have a current backup. If there are any doubts about the 4.2.2 ROM flashing a bootloader, don't do it if on MJB.
Last edited by poppo101; 11th January 2014 at 01:58 AM. Reason: fixed link
11th January 2014, 02:02 AM   |  #3  
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Quote:
Originally Posted by xXFl4sh

I am thinking to flash a 4.4 ROM on my S3 I747M. The only thing I am worried about the bootloader. If I flash the latest boot loader can I downgrade it?

Here a scenario

I am on 4.4 kitkat,with the latest bootloader,and I decide to go back to 4.2.2 with the latest bootloader. Is it possible to do that?

most 4.3 aosp roms can run on the mjb bootloader but you have to modify the updater script to include it. but what the post says above if you try to downgrade the bootloader from mj2 ATT then it will brick the device
11th January 2014, 02:28 AM   |  #4  
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I have the MVLDLK4 bootloader. The only thing I am worried about is that there might be a few errors while using the ROM. I have tried about 3-4 4.2.2 ROMS but there is always 1 or 2 errors eg. Wifi does not work. Since there is only a few roms on 4.4+, i am worried I wont get a stable rom with minor error.

Cause If I update and the rom has errors, I have no backup rom.
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