Driver board switch matrix resistors R204-R211
System 3 driver boards have 1000 ohm resistors at R204-R211, a later version has 330 ohm, and System 7 boards have zero ohm (jumpers). A System 7 driver board works in older games, but an unmodified older board may misread switches in a System 7 game. Fitting zero ohm jumpers at R204-R211 makes any driver board work in any System 3-7 game.
Systems
Related tips
- Logic-probe the switch matrix
- Switch matrix connector pins and their chips
- Switches missed in a System 7 game with an older driver board
- Switch matrix column test at 2J2 with Leon's code
- Switch matrix row test at 2J3 with Leon's code
- Whole game dead after working on a flipper EOS switch
- Make a System 3-6 driver board work in any game
- Switch column or row fault on the driver board
Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part One, Clay Harrell (pinrepair.com)