A solid black block covers majority of screen - all else works

your closed caption system is turned onn to its TEXT FUNCTION use your remote to find the CC or closed caption option and turn it off and the block will go away . good luck

That becauce ur captions functions is on.Tries find the CC on ur remote and turn it off.Or go to ur tv menu find the captions functions turn everythings off,like CC1 CC2 TEXT..

you have to use the remote to turn off the closed caption. But I am sure that is the problem

Most likely it's the closed captioning has been turned on. From your post I assume you have the remote control and able to access the menus so try to turn off the closed captioning. I'll be notified if you post something new.

Are you using an hdmi cord or av cables?

i have the same problem, when i turn the volume knob on hitachi remote it goes away. Anyone heard of thi s???

Go to menu then video menu turn off caption. now this should stop black box in middle of picture.if not under video look in pip menu turn off.

try checking the captions button, labeled CC.....or in menu under captions. It must be turned on or is in text1 mode

Shut off the closed captioning and your problem will be gone.

The first thing to check is for loose conections,the problem is related to the high voltage but it can start in the main board with one component loose,when the high voltage is developed it goes to what is call the distributor block,a lot of sets have the focus and screen controls coming out of this block for each picture tube,this block might be bad but before we go to him we need to check everything is solid in the main board.If you are familiar with electronics you can remove the back cover and tap the chassis with a wooden or rubber handle to see if the set reacts,if it does you need to be atentive what area makes it react and flip the board to do some resoldering,If you are not too familiar with tv service you need the assistance from a servicer.Let Us know how it goes or if you need more information.