At power-on the game pulses coils, blinks lamps and counts the displays quickly.

Stern M-200 game fires coils and counts displays at power-on

Cause: The M-200 enters its self test when all 32 DIP switches read off: either they are all off, or PIA U10 is bad and reads them as open.

Checks

• Check the DIP switch settings.

Fix

• Set the DIP switches, or replace U10.

Systems

• Stern MPU-200

Related tips

• Stern games from 1980 on need an M-200 MPU
• Stern M-200 MPU jumper settings by ROM set
• A Stern M-200 set for 2732s runs any Bally or Stern game 1977-1985
• Using a PC power supply as an MPU bench supply: which wires
• After the test EPROM: refit the game ROM and count flashes
• MPU LED never lights at all
• Power and ground pins of the main MPU chips
• M-200 with all 32 DIP switches off runs a built-in self test

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