In this technical walkthrough, we examine the NIHON KOHDEN TEC-5521 defibrillator's operation panel and demonstrate the UR-0316 keypad component. You'll see how medical professionals interact with this critical interface for energy selection, mode changes, and system control. We'll also show the built-in diagnostic 'Check Key Screen' functionality used by service technicians to verify proper keypad operation and discuss replacement procedures for this essential medical device component.