Try this, turn on your computer on without the TV hook-up, and change the display settings to default then shut it down. Now, connected the TV to any HDMI equipment you have except your computer, if you don’t have anything else. Turn the TV on and select between the inputs to reset the default video inputs and turn TV off. Turn computer on and when computer is fully started connect TV to computer. Turn TV on then go to Display Panel and change the settings.
Hope that’s all there is to it.