Hello! It sounds like there are a few things that could actually be going on. If you are getting no picture on the TV(you have a black, blue, or snowy screen), you will want to make sure that the TV is on the correct channel and/or input. You will want to be on channel 3 or 4, and possibly on a Video 1 or 2 or HDMI 1 or 2 input. If that doesn't work, then try unplugging the receiver from the power source for about 10 seconds. If you are still not getting a picture, let me know!
If you have a signal loss message on your screen (Signal has been lost, Partial SIgnal loss, COmplete signal loss, or Acquiring signal), you will first want to unplug the receiver from the power source for 10 seconds. You will get the Acquiring singla message as the receiver reboots after you plug it in, but that should only be about 5 minutes at the most. If you get the message after 5 minutes, you will want to make sure that all of the cables going from the back of the receiver to the wall are tight. If that still doesn't do it, please let me know!
DISH Network Customer Service