No plug at CPU 1J18 means CPU-controlled special solenoids
Connector 1J18 carries the direct special-solenoid switches on Fire! and earlier games. Big Guns and later do not use it, so an empty 1J18 tells you the special solenoids are fired by the CPU.
Systems
Related tips
- Controlled solenoids 9-16
- The six special solenoids (pops, slings, kickbacks)
- Special solenoids dead after fitting an early System 11 CPU in a later game
- How System 11 A/C switched solenoids work
- Whole groups of coils or all flashers dead: A/C select relay stuck
- Lizard eye flashers locked on, then not flashing: bad drive parts and a missing resistor
- One pop bumper weak and sluggish though coil and switches are fine: replace Q77
- Pop bumper or slingshot machine-guns or locks on (Fire! and earlier)
Source: Repairing Williams System 11 Pinball 1986 to 1990, Deel 1, Clay Harrell (pinrepair.com)