On our tv screen is a big black square on the bottom of the screen we dont have the orignal tv remote

If you have tried using different input devices, looked for loose contacts
in power outlet, RC Jack, cable and connectors, the TV might need service.

Check your TV's closed-caption settings. You have it set for "text" mode now, and the set is blanking out the area where the text would go if there was any.. Turn captions off or set to regual caption mode and the box will be gone. (It's easy to get into this situation because most remotes have a single button to control captions. If it gets pressed you can change modes without knowing it.)

Can u get into ur tv menu with the universal remote?If u can't tries it with the tv manual buttons look at on the botton of ur tv have manual button said menu.Press it go into the tv menu.Look inside the tv menu for functions like Close Caption like CC1,2,3 and Text 1,2,3 make sure all CC1,2,3 and Text 1,2,3 turn it to all off.Black square box will disapear.Can't do it in the tv manual button etheir.Try website like Remote.com to buy the tv origial remote to close Close Captioning and Text 1,2,3 to all off.

This is an aspect ratio issue. On the remote there is a button for changing the ratio to either 16:9 or 3:4. I think it depends with ones remote control but the button has a square as its label. Try looking for it or refer to the user manual. That would be my first guess.

go into your menu and access the closed caption modes. someone has accidently put your tv in the "text" mode. turning off the closed caption feature will correct this.

unplug the set for a while , but this problem will return because of a malfunction in the EPROM CHIP , this controls the menu and a few other functions

It turns out that the Closed Caption option was turned on somehow. When I turned that off the Black Square went a way and did not return.

That when you enabled the Parental Control ON. Try to turn it off. But you need the 4 digit code do that. And if you dont know try to call 800 company number and ask how to reset the TV for factury default. Good luck Hope this may help you Pls. rate me

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

I’m happy to help further over the phone at https://www.6ya.com/expert/dewayne_4a10eab6caecdb92

if your big black square starts about the middle of the tv & goes down close to the bottom, you have closed caption text turned on. normal closed caption is small, but test caption, is just a big black box with no writing in it. go into your menu & shut it off, it could even be a button on your remote called, "caption", or "cc". good luck.