System 4, 6 and 7 boards: one 2716 at IC14 replaces the three game PROMs
These CPU boards have game ROM sockets at IC22, IC21, IC26 (above IC22) and IC14, plus flipper ROMs at IC20 and IC17. The IC15 chip-select change is already made at the factory, so a single 2716 game EPROM at IC14 can take the place of the three 512-byte 3624 ROMs at IC21, IC22 and IC26. Those three sockets are then unused and need not be replaced when re-socketing the board.
Systems
Related tips
- System 7: the 2532 goes in IC17, the 2716 in IC20
- Flipper ROMs at IC17 and IC20: replace the originals with new EPROMs
- Leon's test EPROM: what to burn and where it goes
- Run Firepower on a System 7 CPU board
- Seven-digit scoring on six-digit displays for green-ROM games
- System 3/4 sound board jumpers for 7641 PROM vs 2716
- Leon sound board test EPROM
- Garbled or partial sounds from bad ROMs or sockets
Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part Two, Clay Harrell (pinrepair.com)