From Vivid Unit
This is the approved revision of this page, as well as being the most recent.

When Vivid Unit has power supply connected and is not running, you may press the power button and hold it for one second to turn it on.

When Vivid Unit is on, you may single tap the power button to close the display only. If you want to turn Vivid Unit off, you may press and hold the power button for a few seconds.