The black square / box is associated with the text function on the TV even although the TV might not be receiving it, and this is a procedure that gets over the problem on "some" chassis. If you have a "closed caption" button on your TV's remote control press it until the black square disappears. (On JVC sets this can be a small button labelled "CC") However if you don't have that button on your remote control try this / Bring up the menu and highlight "closed caption", to access this menu press the "volume +" button. When you enter this menu it will say "mode text" Press the "volume +" button until it says "mode off", then press the "channel -" (minus) button and highlight "finish". Finally press the "volume +" button to save your settings. PS: If you do not have the original control and are using a replacement type, then it can be extremely difficult to remove the caption, if able to at all!!.