I have a Roku Ultra connected to a Samsung UHDTV with HDMI. Occasionally while watching TV the screen will go black and audio will cut out, then after a few seconds it comes back on. I have changed HDMI cables and the HDMI port on the TV (moved cable from HDMI 2 to HDMI 1). The only way to get it to stop is to physically pull the power plug, wait a few seconds, then plug it back in. This will "fix" it for a few weeks to a month, then it comes back. It is definitely the Roku causing the issue. Let me tell you, this did not go over well during our Super Bowl party...
I just bought Roku ultra, connected to my brand new sony 4k tv and it worked fine. I switched tv off came back in a couple of hours and Roku will not connect to tv. I have changed HDMI cables, followed all the suggestions online but nothing works - No signal to tv. The Roku power light is on and not even flashing. I need a solution.
You pulled the power cord to the Roku, waited a few seconds, then plugged it back in?
On my 65" LG HDMI is the ARC. Are you able to test it on another TV to check what the Roku unit is trying to set itself at? I have mine running through 1 and then audio out through the ARC but that's just the preferred way for my sound bar and speakers and prevents lag that I've experienced through Optical when running out of the TV.
If I could create the issue on demand then I would be glad to move it to another unit and test it. But, seeing as how it might go three months without having the issue and then do it three or four times over the course of a week, then go back to normal again, it’s kind of hard to do that. I don’t want to buy another Roku unit just so I can move this one around.