I have the exact same issue you’re describing on a Roku Ultra LT purchased in 2022. It randomly stopped displaying any video a few months ago (summer 2024). It doesn’t even boot into the UI, but both of my TVs detect that a device is plugged into the HDMI port and the white LED on the Roku is permanently illuminated. The Roku does not respond to any button presses on the remote (the LED doesn’t blink when a button is pressed either) and holding the physical reset button does not have any effect. My guess is that an update failed to apply and there isn’t even an OS for the device to boot into at this point. Unfortunately, I don’t expect Roku to do anything about it since it is out of warranty, but it’s disappointing that the update process on these devices doesn’t have a failsafe to prevent bricking the device.
