Monopoly Roll N go uses and optical encoder to senses the movement of the di on the game. The right side of podium has access to the encoder disc and sensor. Check to ensure disc is centered to sensor If there is dust or debris on the sensor carefully blow it out. At the encoder sensor the red wire is power for the encoder which should always read 5vdc, the black wire is ground, the white and green wires are the signal lines. The signal lines for the encoder when referenced to ground will be 5vdc going to 0, or 0vdc going to 5 when the sensors are blocked and can be traced back to the P4 connector of the WE2034X I/O board located below the monitors. When replacing the sensor make sure the disc is centered in the sensor.