TV turns on black. omes on says click ok. I click ok and it goes black. I l

Turn on TV. It goes black. After long wait pic comes on, says click ok. I click ok it goes black. I press Guide it shows guide fo about 1 sec then goes black. Also when i click those tjings there is a good bit of hesitation before something comes up then immediately goes black. What could this be. Please help.

All other TVs in house work great. Oh i do have a 6 and 9 year old that think they know everything so it could be a setting. I don't know where to begin.