Bussed versus isolated resistor networks on the CPU board
A 10-pin network marked like "560 x 9R" is bussed: nine resistors share one common pin, marked with a white square on the board. An 8-pin network marked like "1K x 4R" is isolated: four separate resistors, two pins each.
Systems
Related tips
- Replacing SRC6 with a plain bussed resistor network
- Testing a resistor network with a meter
- Random slam tilts: replace the SRC6 resistor pack on the CPU board
- Find the short before refitting a repaired CPU
- Early System 11 CPU connector 1J9 was never used
- Decide whether a phantom switch is in the playfield or the CPU board
- Row or column error: CPU board or playfield?
- Fixing a dead switch column on the CPU board
Source: Repairing Williams System 11 Pinball 1986 to 1990, Part Three, Clay Harrell