The TV did this one or twice now it's pretty much constant. The message comes on the screen about "device is overheating" like some Roku sticks do. Reset doesn't help. It even blinks the indicator light when the TV itself is turned off. If unplugged for a while the message stays off until the TV warms up, about 15 minutes or so and then it never stops. Pretty annoying. If there's no fix for this we might just look into another TV.
Thanks for letting us know about the issue that you are experiencing. It sounds like you may be experiencing a hardware related issue, but it's hard to say.
Please contact your TV's manufacturer directly to report this issue and request additional support. Each Roku TV manufacturer provides direct support for their products running the Roku OS, and can assist you further.
Although TCl was actually very nice and helpful they (as expected) bounced me back here saying the "device overheating" is strictly a Roku error message. Though they build the Roku into their sets, they apparently don't directly support issues with it.