Facing TV Problems? Ask a TV Technician.
Hello, my name is Rusty. Connect it to HDMI 1 ARC/DVI. That TV seems a little gimmicky to me, and I usually see problems with new technologies. Plug it directly into HDMI 1, do not use the USB cable.
Roku doesn't use USB to transfer the video to your TV. It uses HDMI and is compatible with any HDMI TV. Once you disconnect the USB cable (still not sure why that is connected, it's for computer updates), you shouldn't get the message anymore.
HDMI comes with its own power. So does USB. You do not need both. USB is for receiving updates through your computer. The USB port on your TV is for use with a flash drive and a picture gallery.
The only thing that would cause that other than a bad USB port, or a bad Roku, is a bad cable. You mentioned you switched it out and that's when it started happening, is that correct? Have you tried another cable?