The custom firmwares bring several tweaks, modifications as well as boost performance of the Android powered Xperia devices. However, the devices sometimes come across bug issues with the installation of custom ROM. In such situations, users are always recommended to restore the Xperia devices to factory settings, which can be done by flashing stock official firmware.
Xperia owners, who wish to restore their devices to stock firmware, may follow our step-by-step guide. This is an official method to restore stock firmware using Sony Flashtool, which is officially supported and released by Sony. This method will perform complete factory reset on the Xperia device. It should be noted this tutorial is only for the below mentioned Xperia devices.
Supported Xperia devices
Xperia Z (C6603) - Volume Down
Xperia ZL (C6503) - Volume Down
Xperia Tablet Z (SGP321 and SGP311) - Volume Down
Xperia Go (ST27i) - Back button
Xperia Neo V (MT11i) - Volume Down
Xperia Ray (ST18i) - Volume Down
Xperia P (LT22i) - Volume Down
Xperia PLAY (R800i) - Back button
Xperia E Dual (C1605) - Volume Down
Xperia E (C1505) - Volume Down
Xperia T (LT30p) - Volume Down
Xperia S (LT26i) - Volume Down
Xperia Arc (LT15i) - Back button
Xperoa Arc S (LT18i) - Back button
IBTimes UK reminds its readers that it will not be held liable for any damage to the device. Users are also advised to verify that their devices meet following requirements.
2) Enable USB Debugging Mode on phone to connect it with computer and use Android SDK with it. [Press Menu>> Settings>> Applications. From there navigate and click on Development option then check USB Debugging Mode.]
3) As the tutorial might wipe out all data of the phone, create a backup. If the device is having any custom recoveries such as CWM/TWRP installed then backup data using recovery.
4) The Xperia device should have above 80% battery charge.
5) The tutorial works only on aforementioned Sony Xperia devices. As applying this to any incorrect variant might brick the device, verify the model number of Xperia device by navigating to Settings>> About phone>> Model number.
Steps to restore Sony Xperia devices to stock official firmware
Step-1: Download and install Sony FalshTool/Emma on the computer
Step-2: To open Emma, click Start>> All Programmes>> Sony Mobile>> Emma
Step-3: Turn off the Xperia device
Step-4: Pres the Volume Down or Back button while connecting the Xperia device to the computer (Refer to the list above to choose button accordingly)
Step-5: Emma user interface should indicate successful connection
Step-6: Select the appropriate firmware to install on the Xperia device at the Service list. Firmware available will be automatically detected as the computer connect to internet
Step-7: Click on Apply Service at the bottom right corner of Emma user interface. The restoration should take place now
Step-8: Once the official firmware is flashed on the device, unplug the USB cable from the phone to disconnect it from the computer
Step-9: The device will take slightly more than 10 minutes to boot up for the first time
As the Xperia device boots up, it should be running on stock official firmware.
[Source: Android Teen]