Hello, I’m Nathan, and I’ll be assisting you today. My livelihood depends on your positive feedback, so your satisfaction is my highest priority.
Sorry to hear you’re having trouble.
You almost certainly either set the tv to the wrong input mode, or turned off the input device.
First, press the input button on the tv remote (not cable/satellite/etc remotes), repeatedly, pausing after each press, until you get back to the proper input.
If no change, press the Power button on your cable/satellite remote, and then try input again.
If still no results, please reply back with the complete make/model of the tv, and specific details of the hookups - meaning what device is connected and where, for example cable box on hdmi1, dvd on hdmi2, etc