Test EPROM flash codes: which chip failed

Where the LED stops shows the failed part: 1 = EPROM 5C/5B checksum, 2 = RAM 5D, 3 = PIA 5F (solenoids), 4 = PIA 8H (switches), 5 = PIA 11D (lamps), 6 = PIA 11B (display 2), 7 = PIA 9B (display 1), 8 = PIA 7B (sound). The PIA check only reads back the output ports, so input-side faults may not show.

Systems

• Data East CPU Version 1/2
• Data East CPU Version 3
• Data East/Sega CPU Version 3b

Related tips

• Which logic chips drive which solenoid transistor pairs
• One PIA output does not toggle under the test EPROM
• CPU board PIA positions and jobs
• A coil or flasher comes on and stays on at power-up
• How a coil or flasher is switched: PIA to TTL to pre-driver to driver
• Lamp column still dead after a new TIP42
• Switch column (drive) circuit on the CPU board
• Whole switch column dead after working under the playfield

Source: Repairing DataEast 1987 (Laser War) to Sega 1995 (Batman Forever), Part Two, Clay Harrell (pinrepair.com)