Then it's back to the shop for them to exchange it. Why deal with service calls?
I just installed my Visio Smart TV. It worked great for one day but now the screen goes dark just for a second and then resumes. Like it is searching for something. It happens every 2-5 minutes. I am using a cable box with a HDMI cable running to the TV. It is almost like it "blinks" for just a second.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic