Reset Network Settings:

NOTE: Resetting network settings will delete connection data including Wi-Fi and Bluetooth networks, furthermore, default values will be applied to background data sync, data restrictive settings, network selection mode etc.

  1. Open “Settings
  2. Go to “General Manager
  3. Tap “Reset” > “Reset network settings
  4. Tap “Reset settings
  5. If necessary, enter your PIN
  6. Tap “Reset settings” to confirm

Soft Reset via Hardware Keys:

NOTE: A soft reset simulates battery removal and this function can be used when a device is unresponsive. Soft resetting the phone will not delete any personal data located on the device.

  1. Press and hold “Power” and “Volume down” at the same time for up to 45 seconds
  2. Wait for the phone to finish rebooting

Factory Reset

NOTE: When you factory reset a device, all your personal data stored on the phone will be deleted, including ringtones and media files, downloaded content, applications, contacts etc. In addition, all settings will be restored to factory values.

Before your reset the device you can check this thread for a guide on how to back up data, and this thread for restoring data.

Hard Reset via Settings:

  1. Open the apps drawer and launch “Settings
  2. Go to “Cloud and accounts
  3. Tap “Backup and restore” and optionally, enable or disable “Restore” and “Back up my data
  4. Go back to “Settings
  5. Access “General Management
  6. Tap “Reset” > “Factory data reset” > “Reset device
  7. Enter your PIN or password if necessary
  8. Tap “Continue” > “Delete all” to confirm

Hard Reset via Recovery:

NOTE: In case you are unable to reset the device through the above method, alternatively you can try resetting the phone from the Android Recovery menu which can be accessed by performing the following:

  1. Ensure the phone is powered off
  2. Then, press and hold “Home” and “Volume Up” at the same time
  3. Press and hold “Power” as well”
  4. At the “Android” logo, release all buttons and wait for the Recovery menu to appear
  5. Once in Recovery, press “Volume down” repeatedly to navigate to and highlight “wipe data/factory reset
  6. Press “power” to select the highlighted option
  7. Press “Volume down” repeatedly to highlight “Yes – delete all user data
  8. Press “Power” to confirm
  9. Once the reset is done, ensure “Reboot system now” is highlighted then press “Power

See More: Samsung Galaxy A8 Plus (2018): Soft/Hard Reset via Settings or Recovery