First, flip all the DIP switches on the display to ON except for DIP 8, set it to OFF. Power on the display and connect it to the PC.
Download our Display Utility at:
*** RIGHT CLICK THE LINK BELOW TO OPEN IN A NEW TAB ***http://www.raceamerica.com/pcsw.html and run it on the PC. Select the PC COM port for the display and you should be able to send ET and other things if the display and cable are working.