Conjuror, it sounds like your dish is not peaked. Throw rocks at the Voom dish until the picture improves sufficiently. This worked for me twice this week.
Also, make sure your phone jack is connected. That can cause a loss of picture because the satellite signal enters from the phone jack.
Another common problem is a frozen remote. Bring a pot of water to a boil, place your frozen remote into the boiling water, and chant "James Dolan Sux" 12 times forward, then 13 times backward.
If that doesn't work, open the little door in front of the Voom stb, and you know that little red button? Press that little red button exactly 546 times. That will put the stb into revised encrypted MPEG-73296 dystellullar mode. Be careful to press the little red button exactly 546 times, not 545 times, and certainly not 547 times. If you accidentally push it 545 times, the embedded nuclear reactor ignites and could blemish your video console. And if you accidentally push it 547 times, James Dolan's portrait burns itself into your HDTV screen and onto your wall across the room. That happened to my neighbor.
I hope this helps. Please post, let us know how it goes!