if their is a problem with your digital data your picture will not show up. because of the way the bits and data is stored is impossible for you to get only say a sub par picture from it. You will either have the picture or it will be either pix elated or a blank screen, you can amp it and un amp it all day long behind your tv it will not change the digital picture. If your carrier level is high on a digital band its the same as being to low, you will see a black screen or pix elation. if the bit stream is damaged before it gets to your DVR you would either see  a pixeld picture or non at all, you will not see a degraded picture quality as far as image sharpness goes. Its an impossibility.
				
			 
	 
	 
 
		 
 
		 so try the DVR first its the easiet or just change the DVR port, first that may even be easier.
 so try the DVR first its the easiet or just change the DVR port, first that may even be easier. 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		
 
 
		 
 
		