To fix your Roku no signal issue, you can try the following measures.

Try replacing the Roku HDMI cable and check the connectivity.

Check your TVs Input. If it’s on another input mode such as HDMI 2 instead of HDMI 1, change it.Check whether your TV can support Roku’s 1080p resolution.These would fix the Roku no signal issue.For further assistance with Roku no signal, please reach us.