jason_patterson :
i had great signal when i shut my tv off then i came home and turned my tv on and had no signal. nothing changed but i lost my signal. i have tried to search channels again and still have no signal. any help would be great thanks
Could be any number of things. Not really enough information provided here for a concrete solution. So:
If you have a cable connection and the signal is lost, contact your service provider to find out what happened. There may be a service outage for various reasons - installation of fiber optic cables or just repairs due to weather or human accident.
If you have an antenna attached to your TV and it will not pull in any channels but the TV seems fine otherwise, try running your channel detection mode in your TV to restore your channels. It that doesn't work there could be something wrong with your TV.