System 7: the 2532 goes in IC17, the 2716 in IC20

System 3 to 6 boards use two 2716 (or 2316) flipper ROMs, with flipper ROM 1 at IC20 and flipper ROM 2 at IC17. System 7 uses one 2532 at IC17 and a 2716 at IC20. IC20 is mislabelled on many System 7 boards, so check that the 2532 is in IC17 and the 2716 in IC20.

Systems

• Williams System 7

Related tips

• Leon's test EPROM: what to burn and where it goes
• Run Firepower on a System 7 CPU board
• System 4, 6 and 7 boards: one 2716 at IC14 replaces the three game PROMs
• Flipper ROMs at IC17 and IC20: replace the originals with new EPROMs
• Garbled or partial sounds from bad ROMs or sockets
• A System 7 CPU board can run any System 3 to 7 game
• System 3/4 sound board jumpers for 7641 PROM vs 2716
• Convert a System 3 CPU board to a single 2716 game EPROM at IC14

Source: Repairing Williams System 3 to System 7 Pinball 1977 to 1984, Part Two, Clay Harrell (pinrepair.com)