Yamaha RX-V863 trouble

[lykly]

I have a Yamaha RX-V863 that just started "fluttering" the sound and picture. (Rapidly on / off, like stuttering) It is via the HDMI. If I hook up my cable box directly to my TV, no problem. But through the receiver it will not work. It has worked since july prior. The receiver also blinks rapidly with the dolby digital lightds going on and off rapidly. Also the AB speakers light flutter. Prior to this happening, the sound would cut off and say "check Speaker wires";I did and all was OK. All other components work. Any ideas?

 

[Dandle]

Try another hdmi lead.