During firmware upgrade, I made a mistake and it bricks the phone.

So here the steps to restore the phone.

The step is also useful if you would like to reset with original firmware.

Note: The step will wipe all data and restore the phone with the latest firmware.

Pre-requisites:

Install latest Sony PC Companion
Your phone battery at least 80% or more
Plug USB cable to your phone only, follow the step before plug USB cable into computer.

Phone bricks caused by Software Updates.

S1-1. Open Sony PC Companion

S1-2. Click Start on Support Zone

S1-3. Click Start on Phone/Table Software Update

S1-4. Click on the link repair my phone / tablet

S1-5. If your phone model appear in the list, select that model. Otherwise select Another phone/tablet and click Next button

S1-6. Follow the wizard and click on the checkbox to accept the risk warning of Software updates.

S1-7. Select your phone model from the list

S1-8. Keep pressing Volume Down and plug USB cable to computer until you see the wizard shows the circle animation as shown below in picture 5.

S1-9. Software update is now flashing. Do not unplug until the flashing is completed.

S1-10. Flashing is completed. Unplug USB cable from phone and restart phone.