We get a black box on some channels

When you are on the letters virtual keyboard and want to enter a number or a symbol, tap on the box marked '123' or '123Sym'. That brings up the numbers+symbols virtual keyboard. After entering the number(s) or symbol(s), tap on the box marked 'ABC'. That will bring back the letters virtual keyboard.

Look for the CC/Text button on the remote. The TV is in the TEXT mode and is showing garbage that is being sent by the broadcaster, You need to turn the CC/TEXT mode off.

If you put the TV on CH 3 and use a VCR (if available) to change channels you'll know if it's the TV or cable channel (sound like the channel)

Turn off closed-captioning. You'll find it's set for "text" right now, probably from hitting a button on the remote without realizing it. The set is blanking the screen for the text which doesn't show up. (In your case sometimes it does. You're the first person who's ever seen anything that I've responded to!) On channels and programs where captioning isn't being sent the box doesn't show up, so you don't know you have the trouble.

Try and turn off the closed captioning. I had the same problem and it turned out that the closed captioning was on t1 instead of OFF. Hope this helps!!!!

I called Insignia. They said to turn off.... CLOSED CAPTION. It worked.

it is the closed captions on the tv. it is set to closed caption text. turn it off

Your Close Caption is turned on. Search in your menu for Captions, and turn it off.

you have closed captions on TURN IT OFF! this will solve it

Turn off the closed caption