Response pads are a keyboard device using fiber-optic to USB cabling. Fiber-optic cables run from the pads through a wave guide to a controller box which is connected to the stimulus PC via USB cable. Pads may be tested simply by bringing up notepad on the PC and striking the keypad. Blue=1, Yellow=2, Green=3, Red=4 should appear in the notepad. Key strikes will also appear on the controller as blue, yellow, green, and red LED lights. If key strikes are not registering on the control box, cycle power (unplug) to the control box. If LED’s are lighting but the PC is not recognizing key strikes, unplug the USB cable wait 10 seconds and replug the USB cable and/or reboot PC.