Check your power supply for the dish, make sure its plugged in. It looks like a little black box with a green light. Either that is unplugged or a coax cable is unplugged, check all connections inside and out
After checking that and if the problem is still there the best thing you could do is call 18005315000. It will get you to a live rep to help you troubleshoot it more and also help you get a tech out there.
Patleeskunk and tech both gave great advice. However there are two different power supplies for the SWiM system if that is what you have. All SWiM materials are marked with a green tag. If you have a SWiM LNB (part of the dish) you will have one line coming off your dish and going to your power supply. If this is the case the power supply should be black. If you have 4 lines coming off your LNB you should have a SWiM module which looks similar to the old 6x8 splitter, your power supply should be Grey. The color of your power supply is very important because the SWiM module and SWiM LNB use different voltages. 29 Volts for the SWiM module and 21 volts for the SWiM LNB. Improper voltage could cause this problem and I've seen this happen in the past. Hope this helps and please let me know if it solved your problem.
Make sure all the cables connected to your receiver are secure.
You may have a device in your setup that looks like the device pictured here.
http://www.directv.com/cms2/equipment/accessori... This is called a SWiM Power Inserter. Make sure it's plugged into an electrical outlet or an active power strip and the cables connected to it are secure. Do not plug in the SWiM Power Inserter to an power outlet that can be turned off or this could continue to impact your viewing experience.
If all of these connections are secure, try resetting your receiver. On some receivers, there is a small red button inside the access card door on the front panel. Simply press this button and wait for the receiver to reset. If you have a receiver that does not have this button, you can reset the receiver by unplugging the power cord for 15 seconds and then replugging it.
If none of these solves the issue, you may need to schedule a service call. You can reach DIRECTV customer support at 1-800-531-5000.