Clearing the Cache Partition:

NOTE: assuming that your phone is not working correctly, then you might consider master resetting your smartphone. However, master resetting will result in loss of data, so you could try fixing these issues by wiping the cache partition. By doing so, you will not lose personal data.

  1. With the smartphone turned on, press and hold the "Power" and "Volume Up" buttons
  2. Wait for about 3 seconds, until the screen shuts off and the device vibrates once
  3. Release the buttons once that happens
  4. Press the "Power" button to turn on your device, and the cache partition should be cleared

Master Resetting

WARNING! Master resetting your smartphone will result in the deletion of personal data stored on the device's internal memory. This includes downloaded apps, content, custom ringtones, images, contacts and more. Perform a master reset if wiping the cache hasn't solved your smartphone's issues.

Master Resetting via the Settings Menu:

  1. Back up your data if necessary
  2. While on the home screen, tap the "Apps" icon
  3. Scroll to and tap "Settings"
  4. Under "Personal", tap "Back up & reset"
  5. Clear the check box next to "Automatic restore"
  6. Tap "Factory data reset" under "Personal Data"
  7. Tap "Reset phone"
  8. Assuming that you have screen lock enabled, you will be required to enter your password or PIN and tap "Continue"
  9. Tap "Erase everything" to confirm

Master Resetting Using Hardware Keys:

IMPORTANT: the Xperia C cannot be factory reset using hardware buttons, but you can perform the following, assuming that your smartphone is frozen, won't power on or it otherwise prevents you from gaining access to the settings menu, or clear the cache partition:

  1. Press and hold the "Volume Up" and "Power" buttons simultaneously
  2. After about 10 seconds your smartphone should vibrate three times
  3. Once the device vibrates a third time, release the hardware buttons
  4. Press the "Power" key to turn your smartphone back on

Safe Mode

NOTE: In case you've recently installed an application that causes issues on your smartphone, and prevents you from uninstalling it, then you can solve this issue by rebooting your smartphone in safe mode. In safe mode, all third party apps are disabled.

Enabling Safe Mode and Uninstalling an App:

  1. Press and hold the "Power" button
  2. Tap and hold "Power off"
  3. In the "Safe Mode" prompt, tap "OK" and wait for your smartphone to restart
  4. A "Safe Mode" label should appear in the lower-left corner, once your smartphone reboots
  5. To uninstall the problematic app, tap the "All apps" icon from the home screen
  6. Tap "Settings"
  7. Under "Device", tap "Apps"
  8. Swipe to the "Downloaded" screen
  9. Select the desired application and tap "Uninstall"
  10. Tap "OK" to confirm

To Exit Safe Mode:

  1. Press and hold the "Power" button
  2. Tap "Power off"
  3. Wait for your smartphone to shut down, and then press and hold the "Power" button to reboot your device in normal mode

See More: Sony Xperia C: Clear the Cache Partition, Master Reset and Reboot in Safe Mode