I have a Samsung QN65Q6OTAFXZA that I’ve had for about a year, bought brand new. Just a month or so ago the tv auto switches the sound output randomly from optical to tv speakers and I have no idea why.
I even replaced the soundbar but no fix
Exactly the same issue with my UE49RU7300. TV like many previous others connected to Sony Home Theatre system DAV-IS10, ancient but still excellent. Over the past 15 years, we have had 3 TVs and all worked perfectly with sound system till now. Workaround requires two remote controls and TV speakers set to zero. Hope Samsung sort this soon. Very annoying.
Possibly a workaround, similar to something I have seen on a related question on this forum. My TV and sound system now work as they used to with co-ordinated power on / power off and HDMI staying selected. All I did was disconnect all three HDMI devices from the back of the TV - The Sony Sound system was using the ARC port previously as well as the optical port and I have a Humax and Chromecast connected to the other two HDMI ports. I reconnected the Sony to one of the other HDMI ports and left the other ports disconnected. Amazingly, it worked. I then reconnected the other devices and it still works OK. Powered on and off a few times to check. The only difference now is an error message that appears saying "ARC port connected to unsupported device" but that disappears after a few seconds. Can live with that. This did not work when I tried swapping over the HDMI connections in one go. Disconnecting all then reconnecting one-by-one to different ports seems to have fixed the problem for me.
I had the same issue. After long remote battle I found out that my HDMI 1 port have it. HDMI 1 in my Samsung TV is the one with ARC option. HDMI2 and 3 have no ARC. I tried optical option too but it was switching always to TV speakers automatically. Tried new HDMI cable - still the same.
My combination is: Android box(Nvidia Shield) - via HDMI to Sony HD550 - via HDMI to Samsung TV
I switched as main TV output to my Sony HD550 (in TV menu, it was Samsung TV before) and set HDMI cable, from Sony HD550, in HDMI2 port without ARC.
Every CEC options in all devices are turned ON.
Now its working fine. I use 1 remote (android box) to turn ON and OFF all devices.
Only 1 little issue is: when I turn ON everything, TV poopup a message "You connected ARC device to wrong HDMI port. Connect it to HDM1". It last about 5 secs and its gone so is not really issue
I hope it help somebody to resolve problem.
I’m having the same problem with a QN65Q90RA with an older but ARC supported Panasonic surround system. Everything worked perfectly until about a month ago when the sound system stopped switching on with the television and the the source auto-switches back to TV speaker after about 10 seconds if I try to force it to “Receiver”. After combing forums and trying everything I could find, including replacing cables, the work around I’ve gone with is to move the sound system HDMI cable to a non-ARC supported port on the TV. That allows everything to function as before, but I get a warning on startup that the port is not ARC supported and I have to click OK to clear the message. That’s more convenient than two remotes, but still makes me hate the situation every time I turn on the TV. It seems likely that this problem was caused by the latest software update 1401 since that is the only thing that changed on my end. I hope Samsung reads these posts and corrects this problem. One of the things I liked best about this set is how easy it was to set up, and how seamlessly it worked with all of my peripherals.