If the entire ice maker has failed, the unit will not produce ice even if the tray is filled with water. To test this, manually fill your ice cube tray with water and allow the freezer to freeze the water. If the ice maker does not harvest the ice, dumping it into the ice collection bucket, there is a failure in the entire ice maker and your unit may need to be serviced. If the ice maker does harvest the ice, the problem lies solely in the water feeding mechanism.
Ice makers need to be attached to the municipal water system in order to fill the ice trays with water. Ensure the water line is connected to the back of the refrigerator or freezer, and check to see that any ball valves in the water line are turned on. Remove the ice maker from inside the freezer and see if the water feeder lines are attached and have not leaked, causing ice buildup.
The water valve that opens to allow water to flow into the ice cube trays is equipped with a small mesh or wire screen. This filters out impurities in the water, and helps prevent debris from getting into your ice. Over time, these screens can become clogged, causing reduced flow or completely blocked lines. Remove the feeder lines from your ice maker and clean the screen with a mild solution of soap and water. The water valve screen should be in the water line just before the valve.
The water line between the water valve and the ice maker can become clogged with frozen water. Remove the ice maker and use a hair dryer to warm the inlet tube as best you can. Raising the tube even a few degrees above freezing can be enough to melt the ice and get things moving again. Reinstall the ice maker and see if the issue is resolved. If the ice cube trays are filling with water, but at a reduced rate, there may still be a small amount of ice remaining in the inlet tube. Remove the ice maker and warm the inlet tube again.