I have a Samsung KU6400 TV, and a Samsung HT-F5500 Home Theater that I am using to output the audio through ARC.
When I turn off the TV, the HT goes off, as expected.
When I turn on the TV, the HT goes on as well, but after a few swconds the TV switches the source to the HT HDMI input, and the HT switches mode from D. IN to DVD/BD, diplaying a "No Disc" message.
if I turn the HT on first, it will turn on in D. IN and stay there. It doesn't switch the TV on. When turn on the TV, it will stay in the antenna source and audio will play from the HT, as expected.
But this is very annoying, using that HT big controller to turn it on, switch its mode to TV, than turn on the TV. Or use 2 controllers, or turn on the TV, wait for it to switch everthyng to the DVD player, than switch it back to the antenna.
This is not a random issue, as I see some people saying their TV switches sources randomly, no. It switches only when turning on, everytime.
I'm having the same problem with Samsung 8000 series TV and F6500WZA HT system. I read using your tv remote and entering Mute+7+2+9+Exit would stop the tv from auto switching HDMI ports. I have not tried this yet. Any updates or additional information is appreciated.