Replacing IC5 rarely fixes specials that fail only in test
Only one of the six special solenoids is driven in test by the solenoid PIA IC5, and one is driven from the CPU board across the interboard connector. A special that fails only in test is usually a bad 7408, so test that before swapping PIAs.
Systems
Related tips
- Why the solenoid and switch PIAs fail most
- Test the driver board PIAs IC5, IC10 and IC11 with Leon's code
- Slings and pops all burned at once: CPU lock-up from the 40-pin interconnect
- Slings and pop bumpers feel sluggish: backbox boards loose with missing mounting screws
- Solenoid fuse blows at power-on and solenoids fire: driver board logic chips
- System 6 and System 7 driver boards can be swapped for testing
- Coil locks on and new transistors don't help: a failed 7408 on the driver board
- Kicker coil locks on again after a new TIP122: dead 7408 gate on the driver board
Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part Three, Clay Harrell (pinrepair.com)