I have a Roku Streaming Stick+ that's exhibiting a pretty strange problem with video distortion.
I'm seeing horizontal light and dark bands that continuously roll from roughly midway up the screen to the top of the screen over the course of about 10 seconds. They aren't severe, but they are obvious enough to be distracting when watching just about any video. They occur on the Roku home screen, as well as when watching multiple channels (including Amazon Prime and Netflix).
The distortion looks exactly like video "hum" from ground loop interference, such as demonstrated here: https://youtu.be/GS-6jBk9YPM?t=32
But that doesn't really make sense to me, because I wouldn't expect it to be possible on a digital (HDMI) connection, and the Streaming Stick is plugged directly into my TV HDMI input and powered by the TV's USB port. I've also tried plugging the Roku into my A/V receiver and powering it via a standalone A/C USB adapter, and see the same issue, despite all other devices plugged into the A/V receiver and TV working fine.
It certainly seems like a defect with the Roku, but it's unlike anything I'd expect to see in a digital device. Does anyone know what this might be?
I think this issue is actually coming from my Roku TV, not the external streaming stick, so I've moved the discussion to the Roku TV forum: https://community.roku.com/t5/Discussions/Video-distortion-rolling-bands-on-TCL-TV/m-p/532406