After entering the service menu the icons keep moving to the right by themselves.

Portals icons scroll on their own on an early Baywatch

Cause: Early Baywatch games kept the old latching green button; when it is latched down it acts like a held button.

Checks

• See whether the green button is latched in the down position.

Fix

• Press the green button so it is up to stop the scrolling.
• Make it momentary: take the button bracket off the coin door (two Phillips screws) and remove the C-shaped spring wire on the green switch, using the black switch, which has none, as a guide (Sega bulletin 74).

Systems

• Data East/Sega CPU Version 3b

Games

• Baywatch

Related tips

• Two flipper boards on WWF Royal Rumble and Baywatch
• Baywatch: CPU and display EPROM types and latest versions

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