by isiolia Sun Jul 30, 2017 1:08 pm
First, if it suits what you're trying to do, toggle to the external display only (on a non-Mac laptop there's usually a Function key combo to rotate through modes, or bring the toggle up in Windows 8/10). If you're trying to mirror the display, then unless both screens are the same resolution, it'll usually mean subpar results on one or both.
If you're seeing a black border around the screen, or the picture is bleeding off the sides, then it's an issue of adjusting settings regarding overscan. Unfortunately, how to do that isn't consistent. A lot of TVs I've seen will have it in the zoom settings with different names attached (Just Scan, Screen Fit, Native, etc). For some (usually older) devices, it might take something more involved like renaming the input to PC (or using a specific port).
If your laptop has a discrete GPU (particularly) then you may also want to check for overscan settings in its control panel. Mostly I've had AMD GPUs default to 80% screen size, resulting in a black border on a TV.
Why TVs still persist in defaulting to that when no current standards actually use it, I dunno, but they often do.
You should be able to use a laptop while closed, since you can typically wake it from sleep with kb/mouse input. Obviously, if you need to use the power button, that might be prohibitive, depending on the laptop.