A) Instruct user on proper usage of unit.
B) Perform the keypad test by pressing and holding 0, 2, and OK at the same time. A beep will be heard and MAINTENANCE MODE will appear on the display briefly. Release all keys. Use the SCROLL key until KEYPAD TEST appears on the display. Press OK to select the KEYPAD TEST. Now, press each key on the keypads. As each key is pressed, the display will show which key was pressed. If any keys do not respond, that particular keypad should be replaced.
If the display will not allow access to the KEYPAD TEST, we recommend swapping the keypads with a unit of the same model that is in good working condition. If the problem follows the keypad, then the keypad should be replaced.