Testing the Keypad and Diagnosing Failed Buttons
The keypad used in the Noritsu QSF-V50 is wired as a button matrix. Each button connects two lines of the same 8-pin connector when pressed. This makes the keypad easy to test with a standard multimeter. By checking which connector pins are connected for each pressed button, you can determine whether the fault is in the membrane keypad, the connector, or the Display Control PCB. Keypad assembly ...