The large display blanks intermittently, or the game resets.

192 x 64 display blanks out or the game resets

Cause: The controller's 68000 processor runs at 12 MHz and needs logic power at a full 5.0 V; even 4.9 V can make it stop or restart. Aging connectors and a loose ground strap cause the drop.

Checks

• Measure +5 V on the controller board with the game running.
• Check the ground strap to the display board is tight.

Fix

• Repin the +5 V connector, or fit the direct power harness kit 500-6326-00.

Systems

• Data East/Sega CPU Version 3b

Games

• Batman Forever
• Baywatch
• Mary Shelley's Frankenstein
• Maverick

Related tips

• Large 192 x 64 display blanks or resets (Sega bulletin 106)
• Contents of harness kit 500-6326-00
• Build your own 192 x 64 display power harness
• Large display still unstable after the harness fix
• Large 192 x 64 display power connectors by display maker
• Running the large display on the bench
• Setting up a replacement 192 x 64 display
• The 192 x 64 display makes its own high voltage

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