Hi @DR15,
Welcome to the Roku community!
We understand you are having problems with your Onn Roku TV shutting off. Help is here. How are you powering your Onn Roku TV? What do you see or watch on your screen every time it shuts off? Is the issue happening on all contents or channels, or is it isolated to one content or channel only?
With detailed information, we will be able to assist you further.
Best regards, Eunice
Eunice L.
Roku Community Moderator