Same problem here, UE50NU7400 and Marantz SR6009, I have had nothing but problems after buying this TV, my entire setup is ***** now, I even went so far as to test with a Philips, LG and Sony TV, none of them had any problems with the rest of my setup and both ARC and CEC capabilities worked like a charm.
SOLVED .... at least in my case.
I have a Samsung UA65MU6303 connected to an ONKYO TX-SR393. Initially, I spent countless hours resetting everything each time the ARC connection goes off, and after so much exasperation I think I have found the answer.
Switch ON the AV receiver first before you turn ON the Samsung TV. If you turn ON the SAMSUNG TV first, it seems to stay locked that its ARC port does not have a signal, even if you turn ON next the AV receiver. On the other hand, if the AV receiver is turned on first, the Samsung TV will seek and recognize that there is a signal coming through the ARC connection from the AV receiver.
Switching OFF the AV Receiver first renders the ARC port with NO signal, which the TV locks into. The next time you turn ON the TV, its stays locked that the ARC port has NO signal even if you switched on the AV receiver first. QUEER behavior indeed, but the procedure has kept my system working flawlessly for over a week now.
Won´t work in my case.
"Switch ON the AV receiver first before you turn ON the Samsung TV. If you turn ON the SAMSUNG TV first, it seems to stay locked that its ARC port does not have a signal, even if you turn ON next the AV receiver. On the other hand, if the AV receiver is turned on first, the Samsung TV will seek and recognize that there is a signal coming through the ARC connection from the AV receiver. "
After working for a month or so, my Samsung 82” QLED stopped outputting audio to my Yamaha RX-V685 receiver. I have been racking my brains troubleshooting for weeks. At first I thought my Yamaha was bad so I returned it and swapped it out. Nope. The HDMI 4k HDCP 2.0 compliant cables were tested and working fine. Factory settings were reset. Then I stumbled across this thread as my suspicions that the problem was my Samsung TV were more apparent. Tried unplugging each unit for 10 minutes, then 20, then an hour. Nothing. Nothing seems to restore ARC from my Samsung to my receiver. I have to play streaming apps like Pandora and Netflix on my Samsung bluray player to get audio to my receiver. I am livid and beyond frustrated after spending thousands on a new monitor. No excuse why Samsung can’t provide a software update to fix this. It was working then just stopped. Power cycling does absolutely nothing in my case.
The unplugging thing always works for me and I have not heard of a person that it does not work for. I think in your case, the TV has a hardware issue and hoping it is still covered under your warrantee. I would contact Samsung Support and see if they can send a technician your way.
I personally stopped trying to get the CEC/ARC/HDMI to work as it is still a pain in the AXX to power it down and go thorugh the set-up. However, I'm positive if I went to the system and unplugged it for 10 minutes, the CEC-ARC/HDMI woukd work perfect for as little as 10 minutes and as long as a few days. I have posted what I did and you can go back and take a look.
I started with the 30 second unplug, plugged it back in, turned on my Vizio soundbar 1st, then my JS8000 (with HDMI/CEC already on). Connected to it and controlled volume through the TV. We'll see if it lasts.
My first post is about using a DVD player to enable ARC, it not always work.
2 weeks ago I start using a old android box connected to my receiver! So now ARC always works...
55NU7445 <-- TX-L50 <-- DX3060(Alexis)