Best Denon A/v Receiver How Do I Prevent An Old Denon A/V Receiver From Causing Interference With A New Sony HDTV?

How do I prevent an old Denon A/V receiver from causing interference with a new Sony HDTV? - best denon a/v receiver

The components are: Sony Bravia 42 "TV, DirecTV analog box, 10 + years, Denon receivers, VCR and DVD. If the Denon receiver, I thin diagonal stripes on television and a low hum from the speakers. If the receiver is turned off , no scratches. Strangely seems to affect the TV picture is very clear that if the signal comes from the DVD (and the receiver is turned on). It is a new problem, the problem happened just a week ago. The system was it will be implemented for several months. confused without any interference problems A. little.
I would add that this is not my system. This is the configuration of my friends have done for them. They intend to postpone a high-definition satellite switch one days, but. I've checked for loose wiring, but that does not seem to be the problem.

Thank you in advance.