Error 1 is a home chain sensor error on the player 1 side (Left). The issue is the Home sensor is not able to see the home sensor break and the chain does not know where it is. Check the sensor to make sure it has voltage (12volt) across the red and black wires and you see a 5 volt change in the third (signal) wire when the sensor is blocked. If you get both the proper voltage to the sensor and it sends a signal back when blocks make sure the home sensor break is still on the chain and that it crosses threw the sensor during game play. If not adjust the sensor. If this does not give the proper result then change out the corresponding input chip in the U09 socket.