A) Instruct user on proper usage of unit.
B) Massage keypad and feel for depressed key. Massaging keypad may release a stuck key if present. If message still present, perform KEYPAD test from diagnostics. Access the maintenance mode by pressing and holding the 0, 2, and OK keys together. A beep should be heard and MAINTENANCE SETTINGS will appear briefly in the information window. Press SCROLL until KEYPAD TEST is shown in the information window. Press OK to select the KEYPAD TEST. Press each key on the display. Each time a key is pressed, the information window should display the name of the key. Press OK to exit the test. If any keys do not respond during this test, the keypad should be replaced.