Hisense R6 Roku TV family has sound but no picture

The checks in more detail

If the Roku Home shows fine, the TV works and the picture fault belongs to the device you plugged in, so check that it is on, that its output mode is supported, and that the cable is seated. Lower the device's resolution if the screen goes black at 4K or HDR, and test with the Roku Home to prove the TV. Check the picture settings: in Settings, TV picture settings, reset to defaults, because a backlight or brightness set very low can look like a dead screen.

Check Settings, System, Power for an option such as Screen off for audio, which turns off the picture while sound plays. Power cycle by unplugging the TV for a minute and holding the power button while it is unplugged. If the picture appears for a second at power on and goes dark, the backlight is shutting down for protection, which often means a failed strip. Update the system software through the menu if the picture is visible, and do a factory reset if the settings are corrupt. A cracked or pressure-marked panel is physical damage. Note the status light behavior and record a video of the screen, which helps support.

Check the warranty, usually a year, and contact Hisense support with the model number from the back of the TV, which is needed to arrange service. Photograph or record the screen with a phone camera in a dark room, since a camera often catches a faint picture that your eyes miss, and a clear video of the problem is the best proof when you contact the warranty team. Keep the receipt or order email, the model and the serial number from the back label, and the date of purchase, since support will ask for all of them before they arrange service.