If you have switched your till off, or have had a power cut, you’l need to know where the power button / on switch is. For our recent models of tills, it will be in one of two places, as shown below, when facing the screen, the bottom right-hand corner side as shown on the left, or in the middle on the bottom edge of the screen as shown on the right with the green circle around it:
If you push the button and no light comes on, this would mean that there is no power, so check you have plugged it in at the wall and that the plug socket is turned on.