The tv does not recognize the fact that the coaxial cable is plugged in! It does not show that it is connected in setup

[KOZDOG]

The tv just shows a black screen. It must be that the tv is broken. Because I switched Tv's and it is fixed. It cannot be my cable box or my cable. Because switching tv's fixes it.

 

[KOZDOG]

I read in a different forum that a new Motherboard would fix it for $100.00. I would have to install it myself.