The first step for fixing any ice machine is to determine whether the problem is mechanical or electrical. Potential mechanical problems can include blocked pipes, frozen evaporation coils or insufficiently cool temperatures. Electrical problems can include a failed component or broken wire.
If the problem is mechanical, check that the temperature is zero degrees Fahrenheit at the highest. Then inspect the unit for frost or debris built up around the evaporator coils. Finally, check if the water pressure is high enough.
For electrical problems, disconnect the unit from power. Then use an electric multimeter to probe various points of the circuit to locate the failed component.