You're flipping through the channels when suddenly, a strange black box appears. The box could cover the entire middle of the screen, or just a small strip at the bottom. Sometimes the box has characters or words in it, sometimes it's empty. Either way, it's annoying and blocks your view of the screen. The black box is related to the closed captioning feature on the TV. You can get rid of it by disabling closed captioning on your Sony set.
Check the remote control for a "CC" button. If your Sony TV remote has the button, press it repeatedly until the box goes away.
Open the menu on the Sony TV and check the "Setup" or "Settings" section for a "CC" or "Closed Captions" option. Select the option to turn off closed captioning.
Reset the TV to factory settings. For Bravia TVs, turn the TV on and press and hold the up arrow button on the remote. While holding down the up arrow, press the "Power" button and wait for the TV to turn off and turn back on again. Release the up arrow button when the TV is back on. Other Sony TVs may have different reset procedures, so check the manual.