How to Take a Screenshot
Often, when debugging issues, a screenshot can be really helpful to actually see the problem that's affecting your device.
By visiting https://www.take-a-screenshot.org you can see instructions that detail how you take a screenshot on all major operating system (Android, iOS, Windows, Mac, Linux and Chrome OS).
If you have a problem on a TV connected device, then you need to take a photograph of the TV screen, as most devices do not enable screenshots unless you have some developer options enabled.