Wiping the Cache Partition:

Assuming that your phone is not working correctly and you're considering applying a master reset, then you might want to try and solve these issues by wiping the cache partition first. Unlike master resetting your device, wiping the cache will not wipe personal data.

  1. With the smartphone powered up, press and hold the "Volume Up" and "Power" buttons at the same time
  2. Wait until the smartphone powers off, and until the handset vibrates once (roughly after 3 seconds)
  3. Once the screen turns off, release the keys
  4. Press the "Power" button again to turn the device back on

Booting in Safe Mode:

If wiping the cache partition did not help and you're experiencing issues due to a problematic 3rd party application, then you can remove the app, even if it may cause constant crashes. You need to boot your device in Safe Mode, as 3rd party apps are disabled in this mode. Then, uninstall the app. To do this:

  1. Press and hold the "Power" button
  2. Tap and hold "Power off"
  3. Press "OK" once you receive the "Safe Mode" prompt
  4. Wait for your device to reboot in Safe Mode
  5. From the home screen, tap the "All Apps" icon
  6. Go to "Settings", and tap "Apps" under "Device"
  7. Swipe to the "Downloaded" tab
  8. Select the problematic application and tap "Uninstall"
  9. Confirm by pressing "OK"
  10. To turn off safe mode, press and hold the "Power" button, tap "Power off" and then reboot your device as you normally would

Master Resetting via the Settings Menu:

WARNING! Master resetting your device will result in loss of personal data saved on the phone's storage, including downloaded content, images, applications, ringtones, contacts etc. Master resetting will not affect content saved on the SIM or SD card.

  1. While viewing the home screen, tap the "Applications" icon
  2. Tap "Settings"
  3. Scroll down to "Personal", and tap "Backup & reset"
  4. Clear the check box associated with "Automatic restore"
  5. Tap "Factory data reset" under "Personal Data"
  6. Tap "Reset phone". NOTE: if you have a lock screen enabled, you will need to enter your password or PIN
  7. Tap "Continue" and select "Erase everything" to confirm your actions

NOTE: master resetting via hardware keys is not available on the Sony Xperia Z1s. If your smartphone is frozen, cannot boot and you can't apply a master reset via the software menu, then try doing the following:

  1. Press and hold the "Power" and "Volume Up" buttons simultaneously
  2. Keep holding the buttons until the device vibrates three times (roughly 10 seconds). NOTE: the phone will vibrate once like when you clear the cache, but after a few additional seconds, it will vibrate again
  3. Release the "Power" and "Volume Up" buttons
  4. Press "Power" and try to see if your device can now reboot normally



See More: Sony Xperia Z1s: Master Resetting, Clearing Cache Partition and Booting in Safe Mode