A Roku device randomly turning off is usually caused by the auto power saving feature. This function puts the device in low power mode after 20 minutes of inactivity and attempts to turn off the connected TV. Users can disable this by navigating to Settings > Power > Auto power savings and unchecking the 20-minute timer.

This fix applies to specific models including the Roku Express 4K (3940), Roku Express 4K+ (3941), Roku Streaming Stick 4K (3820), and Roku Ultra (4800, 4802, 4850). For models not supporting this feature, or if the issue persists, users should check power connections. The USB port on a TV may not supply sufficient power, so plugging the device directly into a wall outlet is recommended.

Additionally, checking the HDMI connection and ensuring it is secure can resolve the problem. The Roku remote itself could also be a factor; removing batteries can help diagnose if the remote is sending unintended signals. If the television continues to power off, it may be utilizing its own independent power-saving settings, or another HDMI device utilizing HDMI-CEC could be the culprit.

Disconnecting other HDMI devices one by one can help identify the specific source of the conflict.