I have a UE48H6400AK TV coupled with a HT-E5200 Home Theatre system. I have always run the TV sound through the Home theatre speakers using ARC. I have the TV speaker settings set to receiver, Anynet+ (HDMI-CEC) set to On and Auto Turn Off set to Yes. This has always worked fine for me and I enjoy the superior sound of the Home Theatre system while watching broadcast TV.
Recently after the TV has been switched on for about 20 to 30 minutes the sound goes off then comes back on again but through the TV speakers. When I check the sound settings I find that the audio output has been switched to TV speakers. If I then switch this back to Receiver after a minute or two it again switches back to TV. It will continue to do this until I switch of the TV and let it cool down. When I next switch on the TV the whole thing repeats itself continuously.
I have carried out the following actions:
Changed HDMI lead.
Full reset of TV and download latest firmware.
Full reset of HT and download latest firmware.
I am now at a loss as to what to do next. Could this be a fault with the TV or the HT?