Samsung TV using HDMI cable? If yes, switching to component cables (the red, white, green, blue & orange RCA jacks) will put the matter to rest quickly, permanantly and easily with no loss of quality. A few Sony TV's have also experienced the issue I've heard. Why? too many reasons to list, just Google the two words Samsung and Motorola.
If not, a Samsung TV using HDMI cable, other cabling/wiring issues should be troubleshot. Look for kinks in the cables. If the wires look like someone spilled a bowl of spaggetti back there clean it up a bit. Check for good firm connections at both ends.
The (MoCa) rates to that cable jack in that room might also be too low, a call to tech support for a test would be needed to isolate that, or a meter you could obtain.
If the computer in the set-top-box has become confused, causing poor processing, un-plugging it from the electricity for 10+ seconds then plugging it back in will re-boot it.
Oh incidently, if it IS a Samsung TV using a HDMI cable you have the only set of symptoms for which I've heard Samsung will send you a "hot-fix", but I just switched cables on mine & saved the HDMI for the Blue-Ray player. I like easy sure things, what can I say?
Wow, I hope your not saying my coax might need replacing. It was 13 years old when Fios was installed(coax was installed when we built our house).
I straightened out any tangles in wiring and I isolated the hdmi cable from the rest of the cabling by 6+", and reseated it. So sound comes through the hdmi cable?
Well unfortunately that didn't work. So I guess I need to call customer service.