Tv will not come on....it was on a few minutes ago

Question

ok I have no clue what my kids did.....but I can not get our tv turned on....they came to me and the tv was on but no sound...tried to turn the volumn up on it but manually and the menu screen was coming on after I hit the volumn buttons on the tv...so i tried the remote and the remote will not access the tv (it's the tv remote that came with it)so i turned the tv off to turn it back on now nothing please help me i have a 4 and a 6 year old...everything is plugged in , i have power and i need help