To perform the master reset for an Alpha 100:
  1. Power off the device
  2. Press and hold your finger on the upper left side of the display
  3. Power on the device
  4. Wait to see Do you really want to erase all user data?
  5. Release your finger from the upper left side of the display
  6. Touch Erase
  7. Allow the device up to 20 minutes to acquire satellite data with a clear view of the sky
The device is now reset and ready for use.