Roku tv turns on for 5 mins max and then has a black screen. I have checked the power and switched outlets but it still work stay on after the original onn screen appears
You didnt mention your Roku TV model # and firmware version: Settings/System/About
You'll need to contact the Roku TV manufacturer for service:
https://support.roku.com/article/115006475047
How can I contact the TV manufacturer of my Roku TV?
Use the support links below to find setup and troubleshooting help as well as support contact information for your Roku TV.
When contacting the TV manufacturer, you may need your TV model number. If you cannot find this information on the back panel of your Roku TV, use your Roku TV remote and go to Settings > System > About.
Contact onn. They're the manufacturer, not Roku.
Where can I get support for my Roku TV™?
@Ah347_ -- I note that Roku's contact page for Roku TV manufacturers does not include contact information for onn (a private Wal-mart brand). I've done some web digging and found these links:
Support for current onn Roku TV models: https://onntvsupport.com/roku-tv
Support for past onn Roku TV models:https://onntvsupport.com/past-models