Building a replacement SRC pack from discrete parts
Steps
- Get eight 4.7k 1/4 W resistors and eight 470 pF capacitors.
- Solder a resistor into each of board holes 2 to 9 and join their free ends to pin 1 (+5 V).
- Solder a capacitor into each of holes 2 to 9 too, and join their free ends to pin 10 (ground).
- This gives each line its own pull-up and its own capacitor, as the original pack did.
Systems
Related tips
- No clock at the CPU: U15, U16, C14/C15
- Fit new C14 and C15 for a cleaner reset and clock
- Coil stuck on that is driven through a playfield-mounted power transistor
- Adding the 4.7k base pull-up to playfield power transistors
- System 9 versus System 11 display data
- SRC packs cannot be tested in circuit
- What the SRC resistor/capacitor packs on the CPU board do
- System 11 CPU board part numbers and spotting features
Source: Repairing Williams System 11 Pinball 1986 to 1990, Part Three, Clay Harrell