Symptom: A keypad button sticks or does not actuate when pressed.
Possible Cause: The flex cable from the keypad to SKBIF PCB is damaged.
If any of the 24 wires fail to make connection, or if they have an intermittent connection, the keypad will malfunction.
- Make sure the pins in the connector  on the SKBIF is in good condition.
- Make sure the flex cable  is in good condition. A broken trace or open contact will cause a row or column to be inoperative.
- Replace the keypad if the cable is damaged.