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.
Is there a light on your Roku device? How are you powering the Roku device? Is the device plugged into the TV USB port or it is plugged into a wall outlet? Have you tried switching out the HDMI cable used to connect the Roku device, or using another HDMI port on the TV?
With more information we will be able to assist you further.