Help getting started with Roku devices, including setup, connecting your device to your TV, linking a Roku device to your account at my.roku.com/link, adding channels, subscribing to services, and more.
Can you please provide more information about the issue you are experiencing? What Roku model device are you using that are experiencing issues with? How are you powering the Roku device? Have you tried using another HDMI port as well as another HDMI cable to see if that resolves the issue you are experiencing?
For troubleshooting purposes, have you tried connecting the device that is giving you issues into another TV to see if you are experiencing the same issue?
With more information we will be able to assist you further.
Re: New Roku no longer working on tv but an older roku will work
Do you see anything on your TV when you power up the Roku? Is the white light on the front illuminated and does it flash when you press a button on your remote? Are you using the supplied power adapter or the TV's USB port (if it has one)? One thing to try, unplug the power from the TV for 30 seconds or so and then plug it back in.