WARNING! When you factory reset your device, all your personal data stored on the phone’s internal memory will be deleted, including media files and downloaded content, ringtones, apps, contacts etc. Furthermore, all settings will be restored to factory values.

NOTE: For details on how to back up and restore data on the Samsung Galaxy J3 (2017), visit this thread.

Factory Reset via Settings:

1. Launch “Settings”
2. Scroll to and tap “Cloud and accounts”
3. Tap “Backup and restore” and enable or disable “Back up my data” and “Restore”
4. Go back to “Settings”
5. Go to “General Management” and tap “Reset”
6. Tap “Factory data reset” > “Reset device”
7. In case your phone is protected by a PIN / password, enter it and “Continue”
8. Tap “Delete all” to confirm

Factory Reset via Android System Recovery:

NOTE: If you are unable to reset your phone via settings as described above, alternatively you can try resetting your phone from the Android System Recovery menu, which can be accessed by performing a combination of button presses as follows:

1. First turn the phone OFF if necessary
2. Then, press and hold “Home” and “Volume Up” at the same time, then immediately press and hold “Power” too
3. At the device logo, release “Power”
4. When the “Android” logo appears, release all buttons and wait for access to the Recovery menu
5. Once in Recovery, press “Volume down” repeatedly to navigate to and highlight “Wipe data / factory reset”
6. Press “Power” to confirm the highlighted option
7. Press “Volume down” to highlight “Yes – delete all user data”
8. Press “Power” to confirm
9. After the reset is complete, “Reboot system now” should be highlighted. Press “Power” to confirm and reboot your device

Reset Network Settings:

NOTE: When you reset network settings, all stored connections (Wi-Fi and Bluetooth) will be deleted, and all connection settings will be restored to default values.

1. Open “Settings”
2. Access “General management”
3. Tap “Reset” > “Reset network settings”
4. Tap “Reset settings” twice to confirm and proceed