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 specific information about the issue you are experiencing? Is there a light on the device when you see no signal? How are you powering the Roku device? Is the device plugged into the TV USB port or is it plugged into a wall outlet? Have you tried using another HDMI port on your TV as well as switching out the HDMI cable used to connect the device?
For troubleshooting purposes, have you tried connecting the device to another TV to see if you are experiencing the same issue?
With more information we will be able to assist you further.