CPU jumpers JW1-JW6 for game EPROM size

JW1-JW6 set the U2/U3 EPROM size (both must match). 2732: JW1, JW3, JW5 in; JW2, JW4, JW6 out. 2764: JW5 in, the rest out. 27128: JW2, JW4, JW6 in; JW1, JW3, JW5 out. Nearly every 6803 game uses 27128s. JW1-JW4 are near U3/U4 below the flipper relay; JW5/JW6 are between U9 and U10.

Systems

• Bally 6803

Related tips

• Factory CPU jumpers by game
• Bench-test a CPU board with the 6803 test EPROM
• Test EPROM fitted but the LED does not blink
• What is on the 6803 CPU board
• CPU board test points
• Unplug all but J1 when using the test EPROM in the game
• Find a bad 6803 or a shorted bus line
• Test EPROM memory test does not pass

Source: Repairing Bally 6803 Pinball Games from 1985 to 1989, Clay Harrell (pinrepair.com)