You need to get to general video fidelity & overscan and change the display override to hdmi (if that's what you are using) that how I've fixed mine it wouldn't go from a smart TV to a regular tv. However if you don't have a TV to work on this could be difficult, you'd have to learn the exact button presses to do this.
If you can get to settings (settings buttons move around all the time and can be set up different on profiles but if you aren't logged in you can press Xbox button, hold analog to right for a second (to get to the far side of the popup menu), down, down then A) it's right, down (TV &display options) A, right, right, down (video fidelity & overscan) A, A, Down,(this is DVI), Down(this is hdmi) A, left, A.
If you are logged in and can get to your settings you need to press up, up before starting the instructions because you start on the system category when logged in rather than the general when you are not.
Hope this helps