The term FULL RESET, may be misinterpreted as Sony has defined the definitions.
From the Sony Web Manual below.
If a full reset (restart) of the TV is required
If you have trouble such as the picture not displaying on the screen or the remote control not working, reset the TV with the following procedure. If the problem persists, try the factory reset procedure below.
If an external USB device is connected to the TV, disconnect the USB device from the TV before resetting.
Restart the TV with the remote control.
Press and hold the power button on the remote control for about 5 seconds until the “Power off” message is displayed.
The TV will turn off and then restart automatically after about one minute.
If the TV does not turn on automatically, press the power button on the remote control after 20 seconds.
Unplug the AC power cord (mains lead).
If the problem persists after step 1, unplug the TV power cord (mains lead) from the electrical outlet. Then press the power button on the TV and wait for 2 minutes, and plug the power cord (mains lead) back into the electrical outlet.
HintYour personal settings and data will not be lost after the TV restarts.
Factory data reset.
If the problem persists after a power reset, try a factory data reset.
Note Performing a factory reset will delete all of the TV’s data and settings (such as Wi-Fi and wired network setting information, Google account and other login information, Google Play and other installed apps).
Press the HOME button, then select [Settings] — [Device Preferences] — [Reset] — [Factory data reset].
Select [Erase everything].
If you have set a PIN code on your TV, you will be prompted to input it when you select [Erase everything].