Check the “Scroll Lock” and “Num Lock” keys. If using the 10 key pad and the screen is not acting correctly the “Num Lock” key may not be lighted.
If the workstation is a PC running Windows, then look at the top bar that displays “A-Shell…..”. If the top line of the window is dim then the window is not “active”. Move the mouse cursor into the window area and click on the left key. The top line should be brighter to show that the window is now active.
