Taxi and Police Force display board differences

These games add a third 7-digit numeric display. The lower 16-digit display is used for numbers only, and its unused segments, comma and right-hand mark drive the extra display through a second ribbon connector on the board.

Systems

• Williams System 11B

Games

• Police Force
• Taxi

Related tips

• Left and right 16-character display boards are not interchangeable
• Same segment missing on every digit of one display: loose glass lead
• Same character position dead on every display: digit strobe wire at MPU J2
• Police Force car motor uses two drivers
• Check every segment with the display test
• System 11 alphanumeric displays
• Displays blank but the game plays
• System 9 versus System 11 display data

Source: Repairing Williams System 11 Pinball 1986 to 1990, Part Three, Clay Harrell