Iceball uses a A.C. powered solenoid to control releasing the balls, the game sends a signal to a solid state relay located on the main board tray to active and deactivate the solenoid when desired. Please download the file below for steps on how to troubleshoot the relay and solenoid.
The ball rail assembly uses an optical sensor to determine if the release arm has fully seated in the down position when fired if this sensor is not blocked the game will generate an error and display "SOL" on the score display, when the release arm is in its down position it rests on a gum rubber bumper if the bumper has worn down it can allow the arm to go below the level of the optic generating the error.