Mod3: 2716 at U2 with a 9316 at U6 on a -17 or M-100

Steps

• Leave the four links E8-E10, E6-E7, E3-E4 and E1-E2 in place.
• Component side: find the trace joining pin 18 of U2 and pin 18 of U3 (confirm with the meter on continuity) and cut it between the two sockets.
• Solder side: wire U2 pin 18 to U17 pin 11.
• Solder side: cut the trace to U2 pin 21, then wire U2 pin 21 to U2 pin 24.

Systems

• Bally MPU AS-2518-17
• Stern MPU-100

Related tips

• Mod1: two 2716 EPROMs at U2 and U6 on a -17 or M-100
• Making a 9316-to-2716 adaptor socket
• Run Freedom or Night Rider on a -17 with 2716s at U1 and U6
• -17 and M-100 boards cannot run 1979-1985 games without modification
• Bally -17 and Stern M-100 ROM jumper settings
• Make a stacked-socket adapter to run two 2716s on a stock -17 board
• Failed 9316 ROMs on a -17 board: use a socket adapter instead of modifying
• MPU board test point voltages

Source: Repairing Bally Electronic Pinball Games from 1977 to 1985, Part Three, Clay Harrell (pinrepair.com)