Screen Is Blank, Says No Signal, or Is Fuzzy
Ensure that your set-top box is turned on. In some cases, the cable box has been turned off and the remote is only turning the tv on and off.
Check that your tv is on the correct input setting. Some cable boxes require that the tv is tuned to channel 3 in order for them to work. Others require a more specific input category such as Input 1 or Component 1 for example. If you tried channel 3 and no picture or sound has come back on, there should be an input button on your remote that will take you to the different input settings on the tv. Try each input setting to see if one of them brings the picture back
Check the cables on the box and tv. Ensure all the cables that are connected to the cable box and the tv are completely plugged in. Due to different circumstances, a cable may become loose and/or unplugged. Even a loose cable can cause all picture and sound to disappear.
Reboot the cable box. You can reboot the cable box by simply unplugging the power cable from the box or from the outlet. Wait a few minutes and then plug it back in. The system should reset and the cable should come back on to channel 1.