How to Factory Reset Android when Locked

In unlocked condition, it is easy to wipe / Factory reset device but when it is locked, here’s how you can do it:
  •     Press Volume UP+Home+Power button at a time till Samsung logo appears.
  •     This enters Recovery mode of Android device.
  •     Second option is “Wipe Data/ Factory Reset”. Depending on the Recovery you have installed, it might be third or fourth.
  • Reboot.

Note: Touch screen doesn’t work in recovery mode, you have to use volume rocker to move up and down. To select, press power or Home key.

Factory reset won’t delete anything from SD Card Memory but it will remove all the user apps installed and remove custom settings if any. Default apps are there itself like Gmail, Play Store, etc however you will need to configure with Google account again.