What to do if video is blocky or black while using Live TV Pause
When using an antenna or connecting cable TV without a set-top box, add a 16GB USB flash drive to your Roku TV™ system and pause live digital broadcast television for up to 90 minutes using Live TV Pause. If you forget to pause and miss an important scene, Roku Live TV Pause allows you to rewind and catch up.
- Note: Roku Live TV Pause is only available when watching "over-the-air" broadcast TV from the Live TV input. It is not available when watching live streaming TV from The Roku Channel.
How does Live TV Pause work?
Live TV Pause is only available on the Live TV input of your Roku TV system. A dedicated USB 2.0 compatible flash drive with at least 16GB of storage is required for your Roku device to record live TV. As soon as you tune to a digital channel, Live TV Pause begins recording up to 90 minutes of live television.
To pause the program, press Play/Pause 
on your Roku remote. Even if you do not pause live TV, you can press Rewind 
at any time to rewind the current channel up to 90 minutes, or to the point where you first tuned to that channel. When you tune to another channel, leave the Live TV input, or power off the TV, the place where you paused the program will be lost.
After being paused for 90 minutes, playback begins automatically.
If you need help enabling or disabling Live TV Pause, learn more about pausing live television on Roku TV.
What to do if the video is blocky or black while using Live TV Pause
There a couple reasons why this might happen.
- Check the signal strength - The quality of the over-the-air signal can fluctuate due to environmental conditions. You can check signal strength by tuning to an over-the-air channel and pressing
on your Roku TV remote control. The more bars you see, the stronger the signal. You can sometimes improve signal strength by adjusting the location or position of the HDTV antenna. - Try a different USB drive - The USB drive may have bad blocks or might be too slow for live video recording. The USB drive is tested by the Roku TV during formatting, but if there is a problem with the drive, you may experience sporadic issues during recording and playback of the paused video.