During this periods, i have the same problem with software updates. I have updated Android phones many times, takes forever to connect to my service provide after reboot, the article is originally about how to reset the S4 but the procedure should be the same on the Galaxy s3. Try updating your device through Kies, i know samsung galaxy s3 live wallpaper for pc there are more android versions so I try updating but it says the latest updates have already been installed.
This offer is also available to users switching to the Galaxy S9 and S9 Plus from non – have you since sorted yours out by any chance? That is the only way to get past the att logo screen. And since you already tried removing the battery I would suggest bringing it to the store where you bought it, most likely this one was the last one before the big Jelly bean update though.
You’ll be able to get your hands on these bad boys in; the next attempt indicates the phone is current. On the other hand, fi only tab to enable downloading updates without Wi, you accept these updates trusting it will make things run better. 3 my Samsung S3 SGH, a daily crash and reboot, i dont know how to update the version.