After inserting a DVD disc into the DVD ROM or DVD RW drive, the keyboard shortcut to switch between the LCD screen and TV display does not work.
※ The keyboard shortcut to switch over between the LCD screen and TV display varies from computer to computer. It may be Fn + F7 or Fn + F8.
Due to the design after inserting a DVD disc, the keyboard shortcut cannot work to switch between windows. This is not a hardware issue.
This behavior is also mentioned in the VAIO Manual.
What to do if VAIO computer cannot burn CD or DVD discs?
Why don't the Fn+F8 keys work when a DVD disc is inserted to the DVD-ROM drive?