I have had my MU9000 for about a year and a half. And decided to buy a new receiver that supported ARC and had a few other features that I wanted. I got an Onkyo TX-NR676. I had everything hooked up and running smoothly for about 1 month. After a month my TV no longer recognized the receiver. I found something in a forum online that suggested trying to unplug all of the inputs and the power from the TV, let it sit for about 20 minutes, and then plug everything back in. This worked for about a week.
I contacted Samsung support and they had me do a factory reset. Now the TV doesn't recognize any HDMI device that I plug into the OneConnect box (Every device shows and 'Unknown').
The ARC on my TV is now working again. I am not 100% sure what fixed it but the samsung tech replaced the main board (still had the problem), They then replaced the OneConnectBox (still had the problem), and then the tech called a samsung support number and they instructed us to do the steps below. I'm not sure if it was a specific one of these things that did it or if all three were required but I would suggested trying the steps below but it does not require and replacement parts.
Steps the Samsung support tech (on the phone) had us perform.
1. Turn off the Anynet+(HDMI-CEC) in the settings on the TV.
2. Turn off the CEC on the AV REceiver.
3. Power off both devices.
4. Turn on the Anynet+(HDMI-CEC) in the settings on the TV.
This is only a temporary solution. It may or may not work for a while. I bouth a samsungtv UN75RU8000 and it works for a couple of days or weeks. Then it fails. I have to do all these "ritual" to get it to work again. Today I cant get it to work at all.
