Firepower original ROM layout and jumpers

Firepower is the only System 6 game that fills IC14, IC21, IC22 and IC26 with game code: three 512-byte 7641 PROMs at IC21, IC22 and IC26 plus a 2316 ROM or 2716 EPROM at IC14, with the usual green flipper ROMs at IC17 and IC20. That layout needs J4 fitted and J3 removed (the reverse of other System 6 games), which is flagged by orange stickers on the board and inside the cabinet.

Systems

• Williams System 6 / 6A

Games

• Firepower

Related tips

• Run Firepower on a System 7 CPU board
• Undo the Firepower 2732 change on a System 6 CPU board
• Firepower CPU ROM configuration and jumpers
• Firepower 2732 change when IC15 is a 74139 (diode and pull-up variant)
• Lights up but dead after storage: leaked batteries on the board
• Number-of-players backglass lamps dead after playfield work: reseat the MPU plugs
• Game keeps resetting: replace the 5101 RAM (an NVRAM works)
• What changed on the System 6A CPU board

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