The LED lights on a id card printer show the current status of the printers operations. Different lights and combination of lights will shine as specific functions of the printer are working, in process or malfunctioning.
Many light combinations are simple to understand while it is helpful to keep a printer manual available for correct interpretation of some light configurations.
ID card printers that do not have the LED light function, come with a LCD display that communicates status and errors with text messages. Usually professional series id card printers are equipped with the LCD function while entry level printers will come equipped with the LED light capability.