A pinball machine has been designed with several novel mechanical and electrical features such that it is easily retrofittable or convertible between a first pinball game and a second pinball game. The pinball machine includes a cabinet, a playfield, a playfield panel, an electronics system, and a video display. The playfield is mounted in the cabinet with the playfield panel mounted to the cabinet and overlaying at least a portion of the playfield. The video display is mounted generally above the cabinet and is disposed to project video images onto the playfield panel for viewing by the player. When the pinball machine is retrofitted, diagnostics can be performed while the playfield panel is still removed from the pinball machine by displaying diagnostic video images/information onto a partially reflective member positioned below the video display. The partially reflective member may, for example, be the glass or plastic structure that is mounted on the backbox and acts as the marquee for the pinball machine.