[Q] Samsung GS3 i747 - Help Needed

Hello, I'm new to this forum although I've been following most of the threads. I have a Galaxy S3 by AT&T, unlocked and running stock 4.1.1 before I decided to flash to CM. Didn't like a few things about CM so I tried to Odin back to stock 4.1.1. Got to pass quite alright but the phone wont boot back up and now seems bricked. I've read about problems others have had with bricking trying to downgrade from stock 4.3 to other earlier versions on this particular phone model. I, however, thought this was a problem with stock rom only and CM had taken care of the dreaded knox and secure bootloader?

How do I fix this brick and get the phone back up and running? I'd greatly appreciate the steps laid out in plain English a newbie would be able to comprehend easily enough. Thanks

shortydoggg said:

Did you go into recovery and do a factory reset?

Sent from my SAMSUNG-SGH-I747 using XDA Premium 4 mobile app

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Thanks very much! Just did that and it worked.

Update

shortydoggg said:

Did you go into recovery and do a factory reset?

Sent from my SAMSUNG-SGH-I747 using XDA Premium 4 mobile app

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Just wondering then if it's possible to switch to CM or any knox-free custom rom from stock 4.3 on the AT&T Galaxy S3? If so, it would seem to be a convenient workaround to the problems users have expressed trying to downgrade from 4.3 to 4.1.1 in order to free unlock their phones. I mean .. first install a custom rom and then odin back to stock 4.1.1 to unlock and, thereafter, upgrade either back to stock or a preferred custom rom? Would this be possible?

audit13 said:

You can't downgrade from the stock 4.3 bootloader to an older bootloader. Trying to flash an older bootloader will brick the phone.

You need to be on stock 4.1.1 in order to use the free unlock method. A custom 4.1.1-based ROM will not have the required menu options.

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Thanks. Maybe I didn't phrase my question properly ... I mean is it possible to go to from stock 4.3 to a custom ROM based on 4.3 (or newer) e.g. CM11? I understand you can't downgrade from stock 4.3 to an older bootloader which is why I'm asking if a workaround involving stock 4.3 to custom 4.3 based and then back to stock 4.1.1 is possible? I don't know if anyone has been able to successfully flash custom 4.3 based to the AT&T version of the GS3 running stock 4.3.