It appears the previous owner didn't know enough to reset the flash counter before he unrooted.
BEFORE DOING ANYTHING, UNDERSTAND YOU'RE IN THE
SPRINT SUBFORUM, and you absolutely should not follow the instructions in this forum or you'll risk bricking your phone.
You should probably post this question again in the T-Mobile forum, but as a general guideline I think you have two choices. One, leave the phone as it is. You won't be able to get OTA's, but when a new ROM update is available it will probably be extracted and made available in a file that you can manually apply. Two, root the phone, run Triangle Away, and unroot. But make sure you follow the instructions from the T-Mobile forum, and not the Sprint one:
http://forums.androidcentral.com/t-mobile-galaxy-s-iii-rooting-roms-hacks/
Hi,
Sorry for the wrong location.
Can you tell me how I could manually apply the updated Stock ROM once it's available? And If I manually apply updates, will they wipe my user data or still preserve it like how OTA updates do?
And, I did the following process three times, but to no avail
I am not really sure what the problem is.
Here's what I did:
1. Rerooted using Motochopper method (successful)
2. Installed CWM Recovery using Odin v 3.07 (successful)
From Steps 3 onwards, I followed the Guide made by DocHoliday77 from XDA Forum (
http://forum.xda-developers.com/show...hp?t=2308514):
3. Flashed PureStock ROM (successful)
4. Flashed the unmodified, Secure UVAMB7 Kernel (successful)
5. Flashed Stock UVAMB7 Recovery (successful)
* I flashed these using CWM Recovery, not Odin. I wasn't sure how to do it using Odin as I couldn't find any ".tar.md5" files. So I flashed the .zip files using CWM Recovery.
6. From Recovery Mode, I did Factory Reset and Wiped my Cache. (successful)
7. Rebooted Phone, used Triangle Away to reset the Counter. (successful)
Then I powered the phone off, entered the Download Mode and everything was still showing official and the Custom Binary Download showed NO at this point. I then booted the phone up again, uninstalled Triangle Away and then from the SuperUser App, I fully unrooted the phone.
Once all this was done, I powered the phone off again and went to the Download Mode and now the Counter showed YES (1 count), Current Binary = Custom, System Status = Official. So now the Device Status under About Phone is back to Modified again.
I have done this 3 times, if anyone can help me figure out what went wrong, I'd really appreciate it! So frustrated