DIP switch changes seem to do nothing: count the switch numbers correctly

If changing balls per game, credit limit and other DIP settings has no effect, check you are on the right switches before suspecting the board. On this CPU board the switch positions count from the bottom up, and the CR labels printed beside the switch banks are diode numbers, not switch numbers.

Systems

• Bally MPU AS-2518-35

Games

• Fireball Classic

Related tips

• CPU flickers then gives three flashes: bad PIA at U10
• CPU gives all seven flashes, then crashes or won't boot: bad socket at U10
• All DIP switches off can start a self-test after boot
• Changing to 3-ball play: DIP switches 31 and 32
• Masked ROM numbers: keep the set matched
• After the test EPROM: refit the game ROM and count flashes
• Get the MPU booting before you change any ROM jumpers
• Tell a -35/-133 MPU from a -17 by counting J5 pins

Source: Pinball Repair help group!! (Facebook group)