Question What could be wrong with my tv?

[7678carolanne]

All of the sudden my Toshiba tv is going wonky.
It works fine for about 10 to 15 minutes then the picture starts to go in and out. Thought it was the HDMI, but does it does it in color stream as well. All connections are good and tight. What could be the problem?

 

[Rubberduck1]

How does the tv work hooked to cable or open air channels if it does same thing I would say tv is going out