The monitor will turn off if there is not a signal coming into it from a computer or if there is no power connected to it. Make sure the power cable is plugged in and not loose.
Below shows the 3 most common connections in the clinics. Make sure the connector is firmly plugged in and not loose. If there are screws being used to keep the connector in its place, make sure those are tight. Make sure the connector on both ends (one end going to the monitor and one end plugged into the computer) are connected.
In order to make sure whether it's just one computer that cannot connect to the monitor, connect the monitor to another computer. If that computer does not connect to the monitor, try another cable going from the monitor to the computer. If the computer does connect to the monitor, submit a ticket.