Restoring bootloader to bricked S3 T999L
Originally Posted by TronMinecraft
Here I hope to outline how I restored my T999 Tmobile S3 to stock firmware after the 4.3 MJC update, and after bootloader bricking the phone. I do assume you are capable of using ADB, ODIN and TWRP. I believe this method will work for other S3 models, but I have no ability to test it. If it will work, firmware and debrick IMGs will have to be found for the specific device. The T999 firmware and IMGs will NOT work with other devices. This will restore to stock UVUEMJC 4.3 firmware. Will not be rooted, but existing 4.3 roots for the device should work.
Great guide, thanks a ton to @TronMinecraft
for this writeup! I've been lucky and haven't bricked my
S3 T999L (the T-Mobile LTE variant), but a relative wasn't so lucky. She took the OTA upgrade and when she wasn't happy with the result tried to just restore to her old 4.1.2 backup. Needless to say she bricked her phone.
So, I can confirm that this method DOES
work on a T999L. However, there are a couple of things to note (these should be no-brainers, but in the interest of saving questions from the newbies out there...) Of course like Tron said, I take no responsibility for damage to your device should you try this. I can only tell you that it worked fine for me. Here's the things to watch out for, listed by the steps in the OP:
4. Make certain that you use the correct PIT file for the T999L. The proper PIT file for the T999L is the one DocHoliday uploaded here http://forum.xda-developers.com/show...1848267&page=3
. Do not use the regular T999 PIT file from @invisiblek
's first post in that thread, which is what was linked to in the OP.
5. Make sure you use the correct firmware for the T999L, NOT the T999. If you're trying to recover from a brick then most likely you're going to want the Original UVAMB7 firmware (JB 4.1.2), since it seems most bricks lately are caused by trying to downgrade after flashing the 4.3 update. Of course if you want to you can also flash the UVUBMK4 (4.3) firmware and get the complete stock 4.3 system, including the bootloader, KNOX, etc.
However, if you're just recovering from a brick and want 4.3 I would recommend not
just flashing the UVUBMK4 firmware directly. Rather, I would flash the older UVAMB7 firmware, and then once your phone is back up and running flash DocHoliday77's UVUBMK4 4.3 Rooted, deodexed_KnoxFREE ROM from http://forum.xda-developers.com/show...370981&page=58
. Once you've done that, just flash the updated modem from http://forum.xda-developers.com/show....php?t=1880987
as needed. This way you end up with the full rooted version of the 4.3 firmware but without the 4.3 bootloader which includes KNOX and causes so many problems with downgrading.
Of course that's just my two cents. I've been running my S3 with DocHoliday's stock UVUBMK4, KnoxFree, rooted ROM with the UVAMB7 bootloader and UVUBMK4 radio for over a month now and haven't had any problems. As always, your mileage may vary.