Th two SEG displays at the top of the header in Kahuna's Big Wave run off of a ribbon cable that goes from the I/O board to a SEG expansion board up to the top Displays. The Larger of the two displays runs off of 24 volts ( 24 Volt power supply is located behind and below the player 1 chain assembly and can be accessed from the back doors), While the smaller of the two SEG displays run off of 12 volts ( These are the main power supplies for the game and can be found under both score chain assemblies). Any display errors are mostly caused by either a failing power supply or most likely a lose ribbon cable feeding information to the SEG displays.