Under-playfield relay boards and the PPB board

Laser War and Secret Service have no PPB board, so their 50 V coils and motors are switched by small under-playfield SMIG relay boards driven by a CPU TIP122. Later games drive 50 V coils from TIP36c transistors on the PPB board, but many still use small relay boards for motors and for switching sections of playfield GI.

Systems

• Data East CPU Version 1/2
• Data East CPU Version 3
• Data East/Sega CPU Version 3b

Related tips

• All L or all R bank coils/flashers dead: PPB relay K1
• Low coil voltage from pitted L/R relay contacts
• Testing the L/R select relay by grounding Q29
• The solenoid L/R select relay and transistor Q29
• Bank select relay and CPU transistor Q29
• Flash lamp resistors on the PPB drop solenoid voltage for 12 V bulbs
• L/R relay burnt or intermittent
• Balls keep launching as soon as a game starts

Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)