Logic chips for the special solenoid transistor pairs
Special solenoid pairs Q2/Q8, Q3/Q9, Q4/Q10 and Q5/Q11 come from the 7402 at 12A; Q6/Q12 and Q7/Q13 from the 7402 at 12B. On CPU revisions 1 and 2 the logic stops there. On revision 3, 12A and 12B are fed by the 7407 at 11C, which is fed by PIAs 8H, 9B or 11D. RA24, C40-C45 and D1-D6 are present on all revisions and can lock a coil on.
Systems
Related tips
- Special solenoid signal paths SS1-SS6 on the CPU board
- Flippers and special coils all dead
- How a coil or flasher is switched: PIA to TTL to pre-driver to driver
- A coil or flasher comes on and stays on at power-up
- Diverter coils dead and flippers live at game over: 7402 at U50
- Right sling locks on at power-up and a pop is dead: bad 7402 at U45
- Coil fires when tested but not in game play: TTL driver chip
- Stern SB-100 sound board screeches until a game sound plays
Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)