So, you finally got the new Jelly Bean update on your Galaxy S3, but one problem—you’ve got Automatic Shut OFF/ Restart Problem now. Is your phone messed up? No, it’s just a tiny bug that some users have been reporting after updating their Galaxy S3s to Android 4.1.1, and there are a few quick ways to get rid of it.
Step 2. Choose Settings among other options and choose About phone.
Step 3. Tap on Software Updates to manually initiate search for available updates for your phone. It might just be the thing you need to
fix this issue. After all, manufacturers are always listening to their consumers to know what the problems are with their device. In Android, updates are often the carrier of bug fixes.
Simply hold down the power button for 10-20 seconds to soft reset it.
Method #3: How to fix Samsung Galaxy S3 that shuts off automatically
Press and hold the Volume Up + Home + Power button simultaneously to hard reset it. Then, when in recovery mode, select Factory reset.
You can also go to Settings -> Back up and reset -> Factory data reset -> Reset device -> Reset everything. Be sure to BACKUP your device before doing this, since it will wipe you phone clean. This is a last resort method.
Method #4: How to fix Samsung Galaxy S3 that shuts off automatically
When your Galaxy S3 shuts down, take out the battery and let your device sit without a power for 10 minutes. That should be enough to drain some energy stored in its capacitors and semiconductors.
After 10 minutes, re-insert the battery and turn your phone on again. This solution is really that simple but proven effective. So, before you actually do something far more serious with your device due to occasional reboot or shut off, do this solution first and see if it works.
All four of these methods have been known to resolve the problem, but the 4th method is the easiest and should be your primary option.