Cant get dvd to work. my kids were messing with the tv to set up wi, now i cant get the hdtv

Question

my kids were messing with the tv to set up wi, now i cant get the hdtv connect to the dvd to work, as the device for this connection does not show. i have also tried to connect with other cables into the input 1 or 2 (input two device option on the device menu has also dissapeared) still no luck. so many varialbles, kind of lost. thank for you help.i tried to change channels and change input conectors and plug in options from both the back of the dvd and the tv