What the display should show at power-on

On dot matrix games (Checkpoint on) the display controller boots first and shows its display EPROM version almost immediately, then a couple of seconds later the CPU EPROM version (often with country) appears. The Simpsons and earlier have no display controller and show only the CPU version.

Systems

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

Related tips

• Game will not boot: GI on, little else happens
• Normal CPU board LED sequence at power-on
• Random resets from the power supply DB1 bridge
• PIA LED stays lit and blanking never comes on

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