Black Box appearing on my screen

Last night the TV was working just fine but this morning the when I turned the TV on it now has a nice big solid black square that takes up about 90% of the screen. It is the same square that you see when pressing the menu button on the remote, except when you click finish the black screen stays there. I do not have the v-chip set to block anything, nor are there any channels blocked. If I perform a scan for the available channels I can see the whole screen but when that is complete the black square comes immediately back into view. This is the same when I change channels, for a very brief moment I can see the whole screen. It is almost like my 17 month old has clicked on some buttons and the DAD cannot figure it out. Thanks for your help- magnavox tv has the same big black box covering most of the screen.  when i use the menu button it goes away for a second... same with any button that i use... like the volume... the box goes away... comes back!  my dad can't seem to get the remote to work now... so i was trying to help him.  this tv is at my parents house.  when i was there i went through the menu but do not remember a cc option.  so could there be another problem? Yes, I have the same problem on my Phillips Magnavox 32" Smart Plus Series TV Model CCS144. I have tried unplugging the TV as described by electech1and the problem returned. During the last of week of March '09 I was using a remote when this happened and I have been unable to rectify the situation except when I press the volume or MENU but the blank square returns. oemccain#gmail.com